@Hassana60243614 , This should not happen usually, my primary anticipation is that the PDI that you are using might have issue since the ServiceNow is planning a new release the PDI's are causing the issue,
Can you share a screenshot of trying to fill in the data on the form, that might help me understand what is going wrong. Meanwhile you can try to refreshing your instance from "https://developer.servicenow.com/dev.do#!/manage-instance" page.
Or else you will have to release and get a new instance instead. But before doing that don't forget to take your update sets for no development loss.
If this answer helps you in any way make sure to Mark this as accepted solution and give a thumbs up this will also benefit others as well.
Regards,
Saurabh V.
