Hi Kamil,
Did you upgrade CommunityCommons recently?
I think this error happens because there are some libraries (.jar files) in your userlib folder that have multiple versions:
- Go to your project in the file explorer (App -> Show App Directory In Explorer)
- Go to the userlib folder.
- Try to find files that have the same name but a different version.
- For example: commons-lang3-3.10.jar and commons-lang3-3.11.jar are the same library but different versions (3.10 and 3.11).
- Delete the lowest versions and the .RequiredLib files that have this version as well.
- In the example above this will be commons-lang3-3.10.jar and a possible .RequiredLib file: commons-lang3-3.10.jar.CommunityCommons.RequiredLib.
- My guess would be that it's one or more of the .jar files that start with commons.
- Try to run the project again.
Let me know if this works!
Hope this helps!
Pedro Voorwinden