java.lang.NoClassDefFoundError: org/apache/tools/ant/util/ReaderInputStream vaadin+gradle+intelliJ

Question

I have been working fine with Vaadin + Gradle + IntelliJ until yesterday night when I introduced SLF4J(logback) logging to my application. Since then I can\'t make

Answer 1

I deleted the .idea folder and that worked for me.

Answer 2

File > Invalidate Caches / Restart... nor did git clean -dfx. Here is what I had to do:

1. Close IntelliJ
2. IMPORTANT: Make sure you have everything commited you care about (you're about to clean your working copy)
3. Run git clean -dfx to clean your working copy
4. Run IntelliJ
5. Select Import Project
6. Navigate to the directory containing your project
7. The select Import project from external model and select Gradle
8. Press Next
9. Make sure the settings on the next page look ok then press Finish
10. The build should now hopefully work

Answer 3

File > Invalidate Caches / Restart... option didn't work for me, but

sudo git clean -dfx worked fine

Answer 4

Try

File > Invalidate Caches / Restart...