Thank you for your post and screen shot.
Checking with other Support Technicians, we have not seen this before, and I realize this doesn't help you.
Go to Activity -> Clients. Are the blank client names listed?
I realize there are many users listed, and I don't expect you to have them log off one at a time, but since the statistics for these two users are fairly active, do you notice if any user (or both users) should be listed but is not?
Are users connecting manually, or via LDAP or Active Directory?
There is a chance that the user accounts are damaged and FileMaker Server cannot recognize them, leaving the entries blank.
Any other information you can provide may be helpful in narrowing down the possible cause.
Hmmm... after a restart of the server machine, I haven't been able to reproduce this problem for the last several days.
To answer your other questions:
- In Activity > Clients, no blank user names were listed there. Although there were several DUPLICATE user names. it looks like many of the computers and iPads at this office are using the exact same user names. For example, every iPad is simply named "iPad". And it looks like many computers are named "Office" or "Michael". I wonder if this could be causing the issue?
- All users are connecting manually. Authenticating via FileMaker's internal accounts via "local FileMaker Pro file".
- No damage in the file. Performing a full recovery on the file reports no damage.
- I restarted the server before doing what you suggested: compare the list of active users on the "Activity > Clients" tab to the list of clients on the "Statistics > Clients" tab to see if there are any missing users. If this problem happens again, I will try that first -- to at least try to narrow down who SHOULD BE listed but might be missing.