@nickst: you checked IDE plugin version is compatible with the libraries being used, the build plugins being used, and all dependencies? That none of your dependencies are in error if doing a Maven or Gradle sync (maybe something important didn’t resolve)? And you invalidated IDE caches (under File menu, invalidate, restart)? And your IDE plugin is enabled and not showing any error in the plugins preference screen? I think 100% of the time when this happens and is asked about, it is some or all of those. If not, there are 100 of these on stack overflow as well you can check for their answers.