Occasionally, I run into a problem where I’ve somehow corrupted my MAME state (usually from unclean exits) and the debugger crashes on a segmentation fault while trying to open it.

This seems to happen more often when the memory viewer is open. The crash report states that the final function called is handler_entry_read_memory_bank<0, 0>::read(unsigned int, unsigned char), so that may well be another clue.

The solution here is to go into the cfg/ subdirectory of your MAME install, and remove or move the ${driver}.cfg file.