You can try following ways, and check if any one of them works -
Method 1
there can always be an issue with Strapi server,
- I restarted the server manually and it is fixed.
Method 2
your user might not have permission to view that field.
you can change permission of a user by -
step 1 - Login to your strapi cms with Admin account and check if you are able to edit that field(the one with no permission), if so then continue with following steps, else this method wont work for you.
setp 2 - click on settings in left panel , select the user , from the list select the user that you want to change permission with, give read write , and other permissions you want to give.
re-login with your account from which you were facing the problem, it should work now
Method 3
There might be a sync issue with your DB, sometimes your data is not synced with your DB, try deleting the field and re creating it.
I hope one of this solves your issue