Unlikely as it seems stopping Anti-Virus may not be enough, it may be necessary to uninstall it completely.
HOWEVER, that being said . . . . I have at times encountered a corrupted file (or a file with corrupted tags) which caused MC to hang or crash upon import when the process reached said file(s).
Try to import perhaps a folder at a time as this may help you to isolate to culprit.
If no luck then maybe try uninstalling your A/V program temporarily.