Checkstyle failing in AS

[moving-bits]

Since recently checkstyle started failing for me in Android Studio. When running checkstyle manually, it reports the following error:
"The scan failed due to an error - please see the event log for more information", and in the event log I find this:

Unexpected Exception Caught
			The scan failed due to an exception: An error occurred while scanning a file.
			Root cause:
			loader constraint violation: when resolving method 'void com.intellij.openapi.application.ReadAction.run(com.intellij.util.ThrowableRunnable)' the class loader 
org.infernus.idea.checkstyle.util.ChildFirstURLClassLoader @61cff809 of the current class, org/infernus/idea/checkstyle/service
/CheckStyleAuditListener, and the class loader com.intellij.util.lang.PathClassLoader @78e67e0a for the method's defining class, 
com/intellij/openapi/application/ReadAction, have different Class objects for the type com/intellij/util/ThrowableRunnable used in the 
signature (org.infernus.idea.checkstyle.service.CheckStyleAuditListener is in unnamed module of loader 
org.infernus.idea.checkstyle.util.ChildFirstURLClassLoader @61cff809, parent loader com.intellij.ide.plugins.cl.PluginClassLoader 
@73d54296; com.intellij.openapi.application.ReadAction is in unnamed module of loader com.intellij.ut... (show balloon)

Any ideas how to fix this?

[eddiemuc]

First thing I would try is installing an older version of the checkstyle plugin. I had (other) problems with checkstyle in the past and solved them this way.

[moving-bits]

Ah, so easy... Yes, downgrading to 5.74 (instead of proposed 5.74.1) seems to help indeed. Thanks 👍