Very strange...This post with our replies is now mysteriously appearing in Our Community section, so I'm replying here again to Lordgiffnock:
Lordgiffnock..I started on Atari too....Lucky you to find those dongles. You can run versions 3 and 4 with them.I think those versions should launch on your Performa. I would suggest try launching 4.7, so you can watch the initialization sequence at the bottom of the startup logo window. I don't have 2.5 handy, but I just launched 2.02 on my G4 MDD dual 1.25 (with errors, of course) and 2.02 doesn't show that info. Does launching 2.5 show that info? Try version 4.7 just to read that info where it might be sticking. That might tell us something. I wonder if a PCI card or any other expansion card is confusing Logic. I suggest temporarily pulling out all OMS extensions (from the extensions folder in the system folder) onto your desktop and let Logic use its builtin drivers for the time being. OMS 2.3.8 installer should contain the X64 driver, however Logic's builtin drivers can find that interface. I doubt no connected interface would cause what you are experiencing. You could also disable ALL extensions by holding down the shift key on startup. Logic 2.5 should still launch with no extensions. That would be a starting point. Keep us posted what happens.