Scans for any unanalyzed files in the current project and indexes them. Reopen Project
Repairing IntelliJ IDEA is rarely a binary choice between tolerating bugs and reinstalling from scratch. The IDE offers a hierarchy of repair techniques—from cache invalidation and safe mode to Toolbox repair and settings resets—that resolve over 90% of common issues. By understanding these tools, you can restore your development environment quickly, without losing your workflow or project state.
To reduce the need for repairs:
: IntelliJ cannot find libraries or classes that are clearly in your classpath.
| Symptom | Likely Cause | Fix | | :--- | :--- | :--- | | | A previous instance didn't close properly. | Delete the cdfs folder inside the project .idea folder, or delete system/caches in the config directory. | | Java OutOfMemory / Heap Space | Project is too large for default RAM. | Go to Help > Edit Custom VM Options . Change -Xmx to a higher value (e.g., -Xmx2048m or -Xmx4096m ). | | Java Version Mismatch | Project SDK not set correctly. | File > Project Structure > Project > SDK . Ensure it matches your installed JDK. | | Font rendering looks bad | General graphics glitch. | Enable "Disable hardware acceleration" in Appearance & Behavior > Appearance . | intellij repair ide
Third-party or recently updated plugins are a common source of crashes and slowdowns.
Use this if nothing else works.
: Red-underlined code that you know is actually correct (often a sign of a corrupted index).
Quickly closes and reopens the project (without a full IDE restart) to refresh project-level caches. Drop Shared Indexes Scans for any unanalyzed files in the current
If the IDE won’t even launch, navigate to the configuration directories manually: