Even if five years have passed since this thread was opened, Im' facing more or less the same problem as the m2e-apt plugin is no more compatible with Eclipse 2024-09, I'm also using Lombok plugin v1.18.34.

My problem was that I ended up getting the ClassNotFound exception while running unit tests mentioned in this thread.

THE SOLUTION From menu Project -> Properties -> Java Compiler -> Annotation Processing

• Select "Enable project specific settings"
• Select "Enable processing in editor" (should be already selected)
• specify in "Generated source directory": "target/generated-sources/annotations"

After that rebuild with maven and perform a Maven Update of the project, run tests.