The Aqua / MacOS-native port of Basilisk (Basilisk II 1.0, Mac OS X port 19, downloaded from
here), 99% of the time, launches, shows smiling Mac, the blue MacOS screen, march of icons as extensions and control panels load, Desktop background loads, then *spoop*, window closes, Basilisk crashes, and that hard disk image is rendered unbootable.
(I can fix the hard disk image by booting either the X11 version of BasiliskII or booting SheepShaver, from a totally different hard disk .img file in either case, and edit the prefs to include the beforementioned crashed Basilisk startup disk as an
extra disk to also mount. Once it has been mounted, that cleans it up and it is again a bootable HD image. I have run MacOS 7-8 era Disk First Aid and Norton Disk Doctor and Mactools Pro utils and they report the imageDisk to be in good working order when I do.)
Hope that's clear and makes sense. The X11 version doesn't crash (or very rarely crashes). The Aqua / GUI version nearly always crashes (can't make it all the way to desktop with drive icons and trash can) but on a few occasions has worked for me. JUST a few. As far as I can tell I didn't make any modifications to settings either within the System 7.5.x environment or to the Basilisk setup. The setup params, by the way, are absolutely identical for X11 and Aqua versions of Basilisk —— they're referencing the same settings and changes made by the standalone BasiliskGUI.app settings interface are reflected by the initial settings screen you get when you execute /sw/bin/BasiliskII from the X11 terminal window, and vice versa. Boots in X11, crashes in Mac-native Aqua. I'd be equally fine with getting the Aqua version fixed or getting networking implemented on the X11 version.
The crashing of the Aqua version is always at the end of attempted bootup; if it makes it to the point of showing the disk icons and trash can, it's usable and stable for the duration of that launch.