Normal Java links still open VS Code despite Codex set to IntelliJ

What version of the Codex App are you using (From “About Codex” dialog)?

26.519.81530

What subscription do you have?

Enterprise

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Codex Desktop is configured to open files in IntelliJ IDEA, but Java source-file links do not open reliably in IntelliJ on Windows. Normal clicks may still open Java files in VS Code, while right-clicking a Java link and selecting “Open in Idea” launches IntelliJ and fails with DirectoryLock$CannotActivateException because the already-running idea64.exe process “is still running and does not respond.” Markdown links started opening correctly after changing the Windows .md file association, but Java links still fail.

What steps can reproduce the bug?

1. On Windows, open Codex Desktop.
2. In Codex settings, set the file editor/open-file preference to IntelliJ IDEA.
3. Ensure IntelliJ IDEA 2026.1.2 is already running.
4. In a Codex response, click a Java source-file link, especially one with a line number.
5. Observe that the Java file may open in VS Code instead of IntelliJ.
6. Right-click the same Java source-file link and select “Open in Idea.”
7. Observe that IntelliJ launch/activation fails with DirectoryLock$CannotActivateException.

What is the expected behavior?

When Codex Desktop is configured to use IntelliJ IDEA as the file editor, Java source-file links should open in the already-running IntelliJ IDEA window. If the link includes a line number, IntelliJ should open the file at that line. Codex should not open Java files in VS Code when IntelliJ is selected.

Additional information

Environment:

• Windows
• Codex Desktop, latest version as of May 28, 2026
• IntelliJ IDEA 2026.1.2
• Java files are associated with IntelliJ IDEA in Windows default-app settings
• Markdown files began opening correctly in IntelliJ after changing the Windows .md file association

Observed details:

• The issue persists after restarting Codex Desktop.
• Some affected Java links include line numbers.
• Right-clicking a Java link and selecting “Open in Idea” produces an IntelliJ startup error:

DirectoryLock$CannotActivateException: Process "C:\Program Files\JetBrains\IntelliJ IDEA 2025.3.2\bin\idea64.exe" is still running and does not respond.

• The IntelliJ install path contains “2025.3.2” because IDEA was originally installed there and later upgraded in place; the running IntelliJ version shown in About is 2026.1.2.
• This may involve Codex’s Java/source-link editor integration rather than only Windows file associations, since .md behavior changed after updating Windows association but .java links still fail.