ISL Light 5.0.2551.64 for Desktop and ISL Light Client 5.0.2551.64 for Mac and Linux (2026-03-18)
General Information
On the 18th of March the following was released:
- ISL Light 5.0.2551.64 for Windows (release_date=2026-03-13, build=14ac6eb03ea26ae43e730725b1f464eb2e11b277, platform=win32,os_version=0x0a000000-0x7fffffff)
- ISL Light 5.0.2551.64 for Mac (release_date=2026-03-13, build=14ac6eb03ea26ae43e730725b1f464eb2e11b277, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Light 5.0.2551.64 for Linux (release_date=2026-03-13, build=14ac6eb03ea26ae43e730725b1f464eb2e11b277, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
- ISL Light Client 5.0.2551.64 for Mac (release_date=2026-03-13, build=14ac6eb03ea26ae43e730725b1f464eb2e11b277, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Light Client 5.0.2551.64 for Linux (release_date=2026-03-13, build=14ac6eb03ea26ae43e730725b1f464eb2e11b277, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
All updates have release date set to 2026-03-13. Your ESS will need to be same or higher to be able to update your server. This release is available to all countries except Japan.
Upgrading to new version
Hosted service users please check Upgrading Hosted Service.
Server license users please check Upgrading Server License.
IMPORTANT:
- Minimal operating system requirement on Windows for ISL Light application was raised from Windows 7 to Windows 10.
- Minimal operating system requirement for ISL Light on macOS was raised to macOS 14.
- Minimal operating system requirement for ISL Light on Linux was raised to require glibc 2.35.
- New ISL Light permissions were added to macOS 26 or later. Customers upgrading to macOS 26 will have to grant the new permission in order for the application to work correctly.
Improvements
Description
ISL Light common code now supports end to end certificates that will replace old static c2c certs. The certificates use EC instead of RSA certificates.
Description
Minimum operating system requirement for ISL Light on macOS was raised to macOS 14.
Description
We have unified look and feel of ISL Light menus and native controls when run in qt 6.10.
Description
Minimal OS requirement for installing of ISL Light was raised to Windows 10. Users on operating system lower than Windows 10 will receive an error when trying to install ISL Light.
Description
Minimal operating system requirement on Windows for ISL Light application was raised from Windows 7 to Windows 10.
Description
An improvement was added in talk plugin which stabilizes the states and communication when using functionality between ISL Light and ISL Light Client on Windows.
Description
Redesigned ISL Light toolbar on operator side for a modern, easier and more intuitive experience. The new toolbar features clear labels, improved icons and more actions like *Session Details*, *Edit Session*, *Video Call*, *Audio Call*. The previous pinning mechanism has been replaced with a simpler show and hide mechanism, which allows the operator to hide the toolbar when not needed.
Description
A button to switch between multiple cameras was added to the Talk interface.
Description
New command line argument was introduced: --add-title "user_defined_title" When used the title of each window will have a suffix with what the users has defined in the command line argument.
Description
Updated icons in ISL Light.
Description
Redesigned ISL Light toolbar on client side for a modern, easier and more intuitive experience. It exposes a couple of new actions, including {*}Session Recording{*}, *Enable/Disable Clipboard* and {*}Topbar position{*}. Along with the toolbar the chat has also been updated featuring a modern UI with vibrant colors.
Description
Added support for extended mouse events in a remote session.
Description
Updated and added new features to session status bar in ISL Light: - Clipboard status is always displayed on the right side of the status bar - Session recording is displayed with an indicator, when it is active - Black screen is still displayed when in use - Streaming remote sound text has also been added when active
Description
ISL Light now uses new schema for securing end 2 end connection. Both endpoints generate public/private keypair and send the public pair has to remote side via ISL Conference Proxy as pre-start message. The certificate used to establish end 2 end connection is then checked by both ends.
Description
A new security dialog was introduced into ISL Light application. It can be found in the Security menu on the bottom left side - Session Security. The dialog hold information about the Session security along with additional information about the connection such as whether certificates were supplied on both side, whether certificates were validated, which cipher suite was used and the fingerprint of both operator and client certificate.
Description
Topbar in ISL Light, also referred to as Control bar, has been completely redesigned featuring a hidden and expanded view. Hidden view shows only a drag area, allowing user to move the topbar around the screen, along with a sharing screen indicator, which expands the topbar upon pressing it. Expanded view allows user to stop sharing their screen, grant or revoke operator control, use local whiteboard tools, chat, make a video/audio call, open main window, hide he topbar and end the session.
Description
In previous versions there was a 5 second delay when creating ISL Light session if there was a session already created and a popup question was shown. We have changed delay to 1 second and removed the popup question.
Description
Added support to display more columns on the computer dashboard in ISL Light. List of all columns: - Alias (default - disabled) - Computer name - *Status (default)* - *Last online (default)* - *Group (default)* - Owner - Shares - Tags - Platform - *Agent version (default)* - IP address
Description
In previous versions video and audio call buttons in ISL Light session toolbar were disabled when connected to an ISL AlwaysOn computer, now these buttons are no longer displayed during such session.
Description
The tooltip functionality in ISL Light was redesigned, the content of the tooltip is now defined just before it appears.
Description
Added support for metrics to the ISLWebViewItem component. This way we can track how often errors with webview happen.
Description
Replaced Session Settings with General Settings in ISL Light.
Description
ISL Light's internal QT library was raised from version 5.15 to 6.10.0.
Description
Updated dropdown items to dropdown squares to reduce the menu cluster.
Description
Added description "This change will not affect sessions that are already running." for settings that do not apply for the current session.
Description
Renamed the View Quality dropdown items.
Description
Added support to automatically close ISL Light session when user stops streaming his desktop. Two new cmdline were added to ISL Light: --on-connect "desktop?close_after_stop" --on-connect "desktop?events=stream_stop_close"
Description
Added icons to the dropdown lists in ISL Light session.
Description
Added support for cmdline to omit a confirmation dialog when ending ISL Light session. The new cmdline argument is "--silent".
Description
Updated security dialog to show Medium when connected with older version of ISL Light.
Description
ISL Light Agent binary was moved to a correct macOS .app bundle called ISL Light Streaming: - daemon install now includes new files ( due to .app structure ) - daemon protocol version was increased to 7 - improved error message in daemon Due to this change, users on macOS 26 will have to grant permissions to ISL Light Streaming process for desktop sharing and accessibility permissions.
Description
We have expanded internal hefa library with: - added function to generate EC private key - added optional tls handshake callbacks - improved logs - mbedtls exceptions now included source context
Description
Added tls_cipher_ok info field to E2E TLS handshake status reporting: - Added cipher and protocol_ver members to tls_status to capture the negotiated cipher suite and TLS protocol version during handshake - Store protocol_ver when protocol_version info callback fires - Store cipher string when cipher info callback fires - On handshake done, report tls_cipher_ok as 1 only when all conditions are met: handshake succeeded, TLS >= 1.2 cipher uses ECDHE key exchange, and cipher does not use CBC mode
Description
Users experienced an issue where border around the input text fields was still displayed even though the focus shifted to another element. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where navigation with TAB/backTAB did not work correctly on login screen if user entered incorrect username or password. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where they were unable to navigate full cycle in chat window with tab/backtab. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
In previous versions the Move to Group Dialog and Remove Group Dialog did not have name set for accessibility features. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
In previous versions ISL Light QML metrics for whiteboard were updated every time the desktop stream started, which should not happen. The functionality was redesigned and now whiteboard metrics are updated when user clicks on whiteboard.
The defect was fixed.
Description
Users experienced an issue where outdated dialog would open when requesting Detailed report from System information. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue when setting whiteboard to delete manually, the setting was not applied an whiteboard was cleared inconsistently. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
In previous versions users experience an issue with gathering log files when connecting via "connect to computer" flow. Functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where chat reports from ISL Conference Proxy were problematic if either operator or client cleared the chat. Functionality was redesigned, when clearing chat it will only clear it in the GUI , but send the full chat to ISL Conference Proxy and also display whole chat if either operator or clients select the option to view chat in chat editor.
The defect was fixed.
Description
In previous versions Meetings button did not have UMA call. Functionality was redesigned, now Meetings button has UMA calls.
The defect was fixed.
Description
Users sometimes experienced crash of an application when QML view was deleted with deferred delete. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
When user opens Join a meeting (in a new window) and then switches tabs to Sessions and back to Meetings tab, clicking Join Meeting will result in "Invalid post token" or "Authentication failed". Handling of session token was redesigned, and token is now restored only if needed. This removes the issue with Invalid post token message.
The defect was fixed.
Description
In previous versions a button in ISL Light Client on Windows was not named correctly for accessibility users. Functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where title substitutions did not work correctly in ISL Light Client v4 for windows. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where they were unable to join to a meeting using ISL Light Client v4 on Windows. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where File Manager was stuck on "Loading" when navigating to a folder with a lot of files. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users sometimes experienced an issue when enabling virtual background on macOS devices. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where ISL Light crashed when the Microsoft WebView2 Framework was missing on the system. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where some columns in ISL Light did not have a size limit, which caused them to take up excessive space. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where WebView windows remained open after the user logged out. The functionality was redesigned so that if a user attempts to log out while a session is still active, a message box appears prompting them to either end the session and log out or cancel the logout. The issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where the "Choose stream quality (Quality Optimized)" setting did not work during an active session. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where the “Enable direct connections” setting did not work during an active session. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where ComboBox did not look the same in QT 6.10 as it looked in QT 5.15. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where the 'F5' key did not refresh application. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where dark theme was applied in ISL Light on windows computer with dark theme. The functionality was redesigned and the issue is no longer reproducible. The defect was fxied.
Description
Users encountered an issue where Local Storage settings did not persist between different WebView windows. Functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users were not able to record ISL Light sessions because the recording folder did not get selected when enabling in session recording. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where white stripe was shown instead of a notification banner in ISL Light. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where the button to reset a value in ISL Light settings did not work correctly. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Custom application icon was not applied on ISL Light Client for Windows. Handling of customization options was redesigned, so custom application icon is now correctly applied to the application.
The defect was fixed.
Description
Users experienced an issue where cmdline '--on-connect "desktop?show&control" did not work correctly when it was used in ISL Light. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where notification that black screen is going to stop was still shown to the remote user even though the black screen was already stopped. Functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced a crash of ISL Light in some cases when access to m_bps_calc_z and m_bps_calc was not protected with m_lock mutex. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where ISL Light session window would blink when user selected a button in new ISL Light toolbar. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users sometimes experienced a crash when ISL Light was calculating the window geometry, due to the screen being null. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where Change Screen Resolution window did not open fully. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where a tooltip text was showing incorrect text when hovering over the button. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where they were unable to see if some menus extend and have to be scrolled in order to see the whole menu. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Operator was able to retrieve clipboard from client even though remote control for operator was disabled. Handling of disabled remote control and syncing of clipboard was redesigned, operator will not receive clipboard from client in case the control is revoked.
The defect was fixed.
Description
Users experienced an issue where some buttons in the new toolbar had missing accessibility and tooltip information. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users were unable to record on session when operator was running ISL Light on Linux. The issue was in file dialog which was replaced with folder dialog after the QT 6 framework migration. After replacing file dialog with folder dialog the functionality is working correctly and users on Linux are able to record the session.
The defect was fixed.
Description
In case users entered incorrect username or password for enabling administration mode, the administration mode did not get enabled however checkbox was present to that item indicating that it is enabled. Checking whether admin mode was successful was redesigned, the checkbox next to enable admin mode should now reflect correct status.
The defect was fixed.
Description
ISL Light application did not inform the operator that incorrect username or password was provided when trying to enable admin mode. Admin mode functionality was redesigned, users will not receive an error explaining that incorrect username of password was provided.
The defect was fixed.
Description
If client tried to minimize the application of the operator from webview, the application stopped responding. Left mouse clicks coming from remote control from webview will now be ignored if they are above minimize, maximize or close buttons in the windows action bar.
The defect was fixed.
Description
Popup type for dropdowns in dashboard specifically under Meetings (beta) tab were changed to be of type window. The issue was that previously dropdown content was not visible which are now visible after switching the dropdown type.
The defect was fixed.
Description
Signup was not shown below the login window. The issue was in set height for the component and thus the elements for signup were not shown. Issue with height of the elements was addressed and the issue is no longer reproducible.
The defect was fixed.
Description
When users wanted to create a non-default tunnel and clicking on New tunnel dropdown the dropdown was blank. Creating a tunnel functionality was redesigned, the dropdown is now correctly populated allowing users to create either RDP, SSH or custom tunnel.
The defect was fixed.
Description
The topbar ( Sharing Screen ) dimensions were incorrectly set and were blocking mouse inputs below the topbar. The dimensions were changed so it now only wraps the topbar and thus allow mouse clicking also just below the topbar.
The defect was fixed.
Description
Users experienced an issue where whiteboard tools did not work correctly. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users experienced an issue where the pointer was not shown on operator side but was shown on client side. Whiteboard pointer tool was redesigned, the pointer is now shown correctly on both sides - operator and client.
The defect was fixed.
Description
MbedTLS cipher suite used was simplified to be similar to server OpenSSL cipher suite. Additionally the following ciphers were removed: - DHE - ECDH - CAMELLIA - 3DES (except TLS-RSA-WITH-3DES-EDE-CBC-SHA)
Description
The macOS daemon updates are now serialized. Before the deamon could be removed from settings or from uninstall/install. The service update is now performed in separate process. Parallel install of launch daemon/agents is now serialized/atomic.
The defect was fixed.
Description
Users experienced an issue in previous version where they were not able to install ISL Light on Windows 10 version 1803 (Build 17134) or older. We have redesigned the functionality and users on any Windows 10 version are able to install ISL Light now.
The defect was fixed.
Description
Users were unable to enable restart and resume functionality due to a limit for ISSC daemon package size. The limit was raised and users can now again enable restart and resume functionality.
The defect was fixed.
Description
Users experienced an issue where the ISL Light application would crash when user joined a session on macOS, enabled R&R and performed a logout. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
Description
Users sometimes experienced an issue where enabling of R&R in a session to macOS would not work correctly. The functionality was redesigned and the issue is no longer reproducible.
The defect was fixed.
