I have no problem with VirtualC64 if I drop the .prg onto emu window. I'm going to upload even a .d64 disk image as well.
Viewing post in Ruote Fumanti (Smokin Tyres) - [C64] comments
I’m using the latest version of VirtualC64 (Version 6.1 - 260901). It works only if I manually drag it to the “Memory” section. If I drop in in the “Drive 8” section it won’t work.
Other PRG files such as “Bubble Bobble - The Lost Caves” would work if dropped on both Drive 8 and Memory slots, so there’s definitely something strange either in the PRG decoding implementation of VC64 or in the PRG file itself.