I duplicated a working database for a different user group, made all the necessary modifications, and it worked for a while. Now the data entry form exits the database upon opening. How can I fix this?

diagnose what is causing the problem

my suspicion is that you have some sort of security / permissions issue
or it could be a form that has problems in its VBA so you may need to do a compile of the code to see if there are any problems and if so fix them.

Sounds reasonable, but I didn't put any security or permissions on it.