[timothyb89]

Looks like the jarfile containing the ZomB classes isn't on your compilation classpath. From the looks of things, simply adding the file via NetBeans like explained above doesn't do anything to the build process (as noted by the dialog). So while the editor's validation may have passed, compilation still failed.

To be honest, I have no idea what the suggested method for adding libraries is for FRC dev. I assume it involves modifying the build file, but so much of that is included from elsewhere it'd be a pain to find the proper place.

Your best/easiest bet, as far as I know, is to copy the source files you need directly into the source for your project and compile the whole thing at once. Assuming the library (ZomB in this case) is simple enough, it won't be pretty, but it should work.
But... if there's a better way, I'd be happy to hear it!

Edit: after looking at the ZomB guide, it looks like copying the ZomB source files is the recommended thing to do.