General Information
On 29th of June 2026 the following was released:
- ISL AlwaysOn 5.0.2551.117 for Windows (release_date=2026-06-25, revision=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=win32, os_version=0x6010000-0x7fffffff)
- ISL AlwaysOn 5.0.2551.117 for Linux (release_date=2026-06-25, revision=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
- ISL AlwaysOn 5.0.2551.117 for macOS (release_date=2026-06-25, revision=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Light 5.0.2551.117 for Windows (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=win32, os_version=0x06010000-0x7fffffff)
- ISL Light 5.0.2551.117 for macOS (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Light 5.0.2551.117 for Linux (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
- ISL Light Client 5.0.2551.117 for Windows (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=win32, os_version=0x06010000-0x7fffffff)
- ISL Light Client 5.0.2551.117 for macOS (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Light Client 5.0.2551.117 for Linux (release_date=2026-06-25, build=8f12e0b60985308fb7c925a3f5cfe77a06b2b021, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
- ISL Pronto 5.0.2551.39 for Windows (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=win32, os_version=0x0a000000-0x7fffffff)
- ISL Pronto 5.0.2551.39 for macOS (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Pronto 5.0.2551.39 for Linux (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
- ISL Tester 5.0.2551.39 for Windows (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=win32, os_version=0x0a000000-0x7fffffff)
- ISL Tester 5.0.2551.39 for macOS (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=mac, os_version=0x0e0000-0x2effff)
- ISL Tester 5.0.2551.39 for Linux (release_date=2026-06-25, build=fb7ac81060a7e3ee8641080b3213d9bf07df8252, platform=linux64, os_version=0x050fc10000022300-0xffffffffffffffff)
This release is available for Hosted Service users.
Upgrading to new version
Hosted service users please check Upgrading Hosted Service.
Improvements
ISL AlwaysOn - Desktop - Track session stage changes (FEATURE) [ISLALWAYSON-2065] More
Description
ISL AlwaysOn now gathers anonymous end-to-end session-stage performance tracking. Each stage of connection is timed and written into UMA metrics. Collected performance can optionally be forwarded to ISL Conference Proxy.
ISL Light - Desktop - Track session stage changes (FEATURE) [ISLLIGHT-7552] More
Description
ISL Light now gathers anonymous end-to-end session-stage performance tracking. Each stage of connection is timed and written into UMA metrics. Collected performance can optionally be forwarded to ISL Conference Proxy.
ISL Light - Desktop - Incorrect CPU usage in System Information on Windows (DEFECT) [ISLLIGHT-6748] More
Description
In ISL Light when you connect to machine you have System Information menu, that shows all most relevant information about machine you are connected to. One of this information is also CPU usage. For machines with Windows operating system we noticed that CPU usage is quite different compared to one in task manager.
The defect was fixed.
ISL Light - Desktop - Substituting ISL Light string is not replaced on all occurrences (DEFECT) [ISLLIGHT-7545] More
Description
Users might notice substitution of ISL Light string not being substituted in Welcome screen and in About window of ISL Light application. The issue was introduced when add title command line argument was introduced. Handling of substitutions was redesigned, both Welcome screen and About window will now show substituted text for ISL Light.
The defect was fixed.
ISL Light - Desktop - Password cannot be retrieved on macOS when run once is used (DEFECT) [ISLLIGHT-7549] More
Description
When users on macOS ran ISL Light using run once mode the password for either login or computer access was not retrieved from Keychain. The issue was a change in singing of application binary. ISL Light is now able to retrieve password from keychain when ran in run once mode.
The defect was fixed.
ISL Pronto - Desktop - Raise os_version version of ISL programs to osx 14 (SPECIAL) [ISLPRONTO-1420] More
Description
The minimum supported macOS version for ISL Pronto programs has been raised to macOS 14.
ISL Pronto - Desktop - Raise minimal OS requirement for InnoSetup (SPECIAL) [ISLPRONTO-1421] More
Description
Minimal OS requirement for installing of ISL Pronto was raised to Windows 10. Users on operating system lower than Windows 10 will receive an error when trying to install ISL Pronto.
ISL Pronto - Desktop - Remove deprecated QT features (SPECIAL) [ISLPRONTO-1422] More
Description
Internal code was updated to remove usage of deprecated Qt features.
ISL Pronto - Desktop - Raise minimal OS requirement on Windows from Windows 7 to Windows 10 (SPECIAL) [ISLPRONTO-1429] More
Description
Minimal operating system requirement on Windows for ISL Pronto application was raised from Windows 7 to Windows 10.
ISL Pronto - Desktop - Migrate code http://*r301 links to https://*r301 AKA safe help page urls (FEATURE) [ISLPRONTO-1423] More
Description
In-application help links now use a secure HTTPS connection instead of HTTP.
ISL Pronto - Desktop - Use PDQ Hancock service for signing executable (FEATURE) [ISLPRONTO-1431] More
Description
Executables are now signed using the PDQ Hancock signing service.
ISL Pronto - Desktop - Clicking on links blanks the page (DEFECT) [ISLPRONTO-1425] More
Description
Fixed an issue where clicking on a link inside a chat message could blank out the message view instead of opening the link in the browser.
ISL Pronto - Desktop - AutoTransport send correct SNI with IP hint (DEFECT) [ISLPRONTO-1427] More
Description
AutoTransport https-direct and wsstun-direct will send correct hostname SNI when using IP hint. httpt-direct and wstun-direct will set correct hostname in Host header instead of IP hint.
The defect was fixed.
ISL Pronto - Desktop - Fix flags dialog on QT 6.0 (DEFECT) [ISLPRONTO-1428] More
Description
The style of window where you can control which flags ( functionalities ) are enabled was having an outdated look. The windows style was adjusted to the modern window.
The defect was fixed.
ISL Pronto - Desktop - Make QT 6.10 work on first Windows 10 (DEFECT) [ISLPRONTO-1430] More
Description
Users experienced an issue in previous version where they were not able to install ISL Pronto 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 Pronto now.
The defect was fixed.
ISL Tester - Desktop - Migrate code http://*r301 links to https://*r301 AKA safe help page urls (FEATURE) [ISLTESTER-122] More
Description
Help page links inside ISL Tester were migrated from http to https.
ISL Tester - Desktop - AutoTransport send correct SNI with IP hint (DEFECT) [ISLTESTER-123] More
Description
AutoTransport https-direct and wsstun-direct will send correct hostname SNI when using IP hint. httpt-direct and wstun-direct will set correct hostname in Host header instead of IP hint.
The defect was fixed.