Stacks...
The STACKS entry in CONFIG.SYS allocates memory for hardware to use. Windows doesn't use this memory, and most modern systems omit the STACKS entry.
You can put a STACKS entry into your CONFIG.SYS file and see if it helps.
I'd suggest STACKS=9,256 would be reasonable. If it doesn't help, try STACKS=18,512. Also, try STACKS=0,0 to disable stacks altogether and see if that helps.
One of these choices, a little, a lot, or none, could do the trick.
Cheers, PW.
P.S. An error may have scrambled your system to the point it displayed the wrong error message -- a comforting thought.