Hi student,

Just check if you have missed to fill some details in student details section or if some information is incorrectly filled ( like not adhering to the prescribed format for photograph/ signature). If this is not the case then try opening site in a laptop or computer if you are opening it in a mobile till now. If this also doesn't work then try to open it in a different browser ( like chrome, Mozilla Firefox, etc.) 

Hope it helps. Let us know if further help is needed.

Good luck