Making Android Studio Quail projects open in tabs again on MacOS

If you upgraded to Android Studio Quail 4 (2026.1.4) on macOS and lost project tabs or the “Merge All Project Windows” feature, you’re not losing your mind. It’s a JetBrains Runtime regression, not an IDE setting.

The culprit is bundled JBR 25.0.3-b508.16, which ships with Quail 4 (tracked as IJPL-253186). Most developers assume their $JAVA_HOME or Homebrew JDK is the problem, but those don’t affect the IDE itself — only Gradle builds. The UI runs on a separate boot runtime, and that’s what broke.

The good news: you don’t need to downgrade Android Studio. Just swap out the boot runtime.

The Fix

1. Download the previous JBR version

   • Go to JetBrains Runtime releases
   • Find version 25.0.3 and download:
     • Apple Silicon (M1/M2/M3): jbr_jcef-25.0.3-osx-aarch64-b329.124.pkg
     • Intel Mac: jbr_jcef-25.0.3-osx-x86_64-b329.124.pkg

2. Open Android Studio’s boot JVM picker

   • Press Shift twice to open the “Search Everywhere” dialog
   • Type: Choose Boot Java Runtime
   • Press Enter

3. Point it to the downloaded JBR

   • Click the folder icon to browse
   • Navigate to your downloaded .pkg file and select it

4. Restart Android Studio

   • The IDE will restart with the new runtime
   • Project tabs and window merging should work again

Why This Matters

The boot JVM is invisible to most developers — it’s bundled with the IDE and only used for the IDE’s own UI. When JetBrains ships a bad runtime version, it affects everyone silently until they discover the workaround.

No $JAVA_HOME tweaks needed. No Gradle config changes. Just swap the runtime and move on.