Live Share Failing to Connect in VS Code Insiders (1.102.0) - Error: 'Cannot read properties of null (reading filesToOpen)'

[matvejs16]

Describe what happened: Suddenly, Live Share has stopped working entirely for me after updating to the latest VS Code Insiders build, specifically version 1.102.0. Whenever I try to join any collaboration session, a modal error dialog pops up immediately, preventing any connection. The error message displayed is "Joining collaboration session: Cannot read properties of null (reading 'filesToOpen')". This makes the extension completely unusable for its primary purpose.

What was your system configuration? Product and Version: VSCode Insiders 1.102.0 OS Version: macOS/Windows 11 Live Share Extension Version: Latest available Target Platform or Language: Not applicable / General connection issue.

Steps to Reproduce / Scenario:

1. Ensure VS Code Insiders is updated to version 1.102.0.
2. Attempt to join any Live Share collaboration session. This can be by clicking on a shared link, or by trying to join collaboration session using link.
3. Observe that a modal error dialog appears immediately with the message: "Joining collaboration session: Cannot read properties of null (reading 'filesToOpen')".
4. Live Share fails to connect, and the session cannot be joined.

Please attach logs to this issue:

[2025-06-13 12:38:15.764 Command:liveshare.joinFromWelcomeContent E] Command [Joining collaboration session]: Join Failure: Cannot read properties of null (reading 'filesToOpen') (1594ms)
[2025-06-13 12:38:15.764 Command:liveshare.joinFromWelcomeContent E] TypeError: Cannot read properties of null (reading 'filesToOpen')
    at handler [PATH]/workbench.desktop.main.js:589:50105)
    at i.handler [PATH]/workbench.desktop.main.js:32:61116)
    at cSt.invokeFunction [PATH]/workbench.desktop.main.js:1306:673)
    at tqe.n [PATH]/workbench.desktop.main.js:1245:3975)
    at tqe.executeCommand [PATH]/workbench.desktop.main.js:1245:3590)
    at k3t.$executeCommand [PATH]/workbench.desktop.main.js:514:529)
    at tkt.S [PATH]/workbench.desktop.main.js:3348:40337)
    at tkt.Q [PATH]/workbench.desktop.main.js:3348:40115)
    at tkt.M [PATH]/workbench.desktop.main.js:3348:39203)
    at tkt.L [PATH]/workbench.desktop.main.js:3348:38307)

Screenshots

The provided image clearly illustrates the error dialog that appears.