I did a test on "Dig It", where I mounted the virtual drive as

C - The game runs normally

D - I got the "Critical Error #005 - File error 103 in "GENERAL.SPF" message.

So, if you're using DOSBox, and have mounted a D: drive as shown here:

mount D [actual path on actual drive], then change it to

mount C [actual path on actual drive] and you should get the game running.