Thanks for posting!
What operating system are you using?
Is this a dedicated machine?
Does this correspond with any scheduled events (FileMaker Server or otherwise)?
Has this ever occurred before?
This is a dedicated Windows Server 2008 R2 Standard 64-bit. All that is on it is FileMaker and usually a dozen or so Clients accessing at any given time.
There were no errors or warnings in any of the FileMaker logs. No activity in the logs at all within an hour < > of the event.
The closest scheduled event was two hours earlier which was a backup of all 84 databases which runs twice a day. Backup time was less than 1 minute.
This is the first and only error since the upgrade to FileMaker Pro Advance Server 11.0.3.
I'm hesitant to suggest any changes with only one instance of the issue occurring. My recommendation is to take copies of the latest back ups to a machine with FileMaker Pro 11 installed and run a consistency check (File -> Recover -> Check Consistency) and Recovery (same process but choose select instead of Check Consistency) to verify the databases aren't damaged.
If everything comes up clean, continue to monitor the machine closely. If one or more of the files do show damage, you'll want to follow knowledge base answer #7336 for next steps on ensuring clean files moving forward as damaged database could certainly cause unexpected behavior in FileMaker Server.
I am currently running a backup of all databases twice a day 0600 and 1200 and a Consistency Check is being performed on all databases as part of the backup. There are no errors reported in any of the logs.
I also copied the databases to a local machine and did as you advised. All clean...
I will monitor and report back if I get the event again.