So your jar files are in the “libraries” subproject, but you’ve now copied the same jars into the “libs” subdirectory of the main project, and now it works? If so, that likely confirms that there’s something wrong with the “libraries” subproject. You certainly didn’t “solve” it, as this is just an accidental hack that manages to not fail your build. Hopefully someone else has a suggestion that might provide more information.
I don’t think so, I created a new project and copied the jar files in the libs folder, so gradle can compile them. I’ve done it with again with another project just to check and seems like it works.
So I assume you’ve gotten rid of the “libraries” subproject? I suppose that’s just as well, there’s not much point in having a subproject just to contain dependencies.