In unosc.prg, new default for _dokje (_WhileIs) is now Key(), so it'll break only if there's a group input without any active index. For that case, I put _dokje=".t." :) (i.e. forever). Added the ability to refuse to add any records if it was compiled as a demo, and the record count exceeds the demo allotment (which was, IIRC, 1000 records).
Later I changed this to check the checksum of few global variables, namely those with the name and address of the company, and if the checksum fits, it's not a demo - that was an add-on in defg.prg. I really hated the very idea of having different versions of the app, even if it took only a change of one option and recompiling. It's an invitation to disaster, for one Murphy would help you pack the wrong version when you needed it most.