In VICE you have this kind of problem when there isn't a disk mounted in the chosen drive.
Viewing post in Briley Witch Chronicles (C64) comments
Thanks @Giovi for your advice. As I know in the meantime it was my bad: the emulator changed a few settings back to the defaults after I have chosen the new crt file. I am using JiffyDos and e.g. "True Drive Emulation" was set to false then as well as some control settings. Once I had set them again correctly also the emulator setup was working again.