I am attempting a MOPAC calculation, but after a certain amount of iterations, the calculation appears to freeze. The calculation isn't finished, but it will not continue.
When a MOPAC calculation is performed, output files are generated in a file called CSMopacOutput. This file is located wherever your Temp folder is defined. The drive that this folder is on is probably full. Do a Find File for CSMopacOutput on your C drive. Delete any files inside or delete unnecesary files on the drive that this folder is on, then retest the problem.