[eschwartz]

Originally Posted by Glorfindel

Try running

calibre-debug --g

in a comand prompt.

Is that a typo, because the proper command is

calibre-debug -g

with one dash. Or you can use the fully-qualified option, "--gui".

Hence the OP's error message.

@Nowaydisnowork, you can try again, it might say something interesting. There are different reasons it might fail.