Hi,

This error may happen if the Roll Number/Testing ID typed is incorrect or password typed is incorrect.

Password is case sensitive, therefore use password which was created by user exactly same as typed while creating. In case password is forgotten, try to generate new password by using security question and its answer.

If this doesn't help, call the helpline number provided on their site.

Hope this helps.

Check out this FAQ also which may help you in further queries-> https://mcc.nic.in/PGCounselling/home/ShowPdf?Type=50C9E8D5FC98727B4BBC93CF5D64A68DB647F04F&ID=6FB84AED32FACD1299EE1E77C8FD2B1A6352669E

Check this FAQ