How can I fix the 500 server error when trying to associate assignee field to a screen?

[Belen Moreno]

I am a JIRA administrator, I have permission to associate fields to screens and I've done it before, but randomly some fields give me errors and I have no clue why.

This time, I wanted to give permissions back to some screens (didn't have error when removing permission, but did have when trying to recover them):

Technical details

Cause

Referer URL: https://hawkers.atlassian.net/secure/admin/AssociateFieldToScreens!default.jspa?fieldId=assignee&returnUrl=ConfigureFieldLayout!default.jspa?id=10101

com.atlassian.jira.scope.IllegalScopedEntityArgumentException: Illegal Entity Scope for Entity class (SCREEN). Expected entity scope 'GLOBAL' but has scope 'PROJECT'

[Steven Behnke]

The way that JRACLOUD-68655 has been worded, it appears that you aren't supposed to be able to change fields on Agility projects.

[Belen Moreno]

None of my projects are Agility ones! They are Software Projects. Does this error depend on the type of project, really?