That's an error message put in by the developers... many, many years ago.
At the time, way back when you could speak with the developers a user was supposed to report that message and document what they were doing prior to the message coming up.
There used to be a few cryptic messages Logic would display when an internal error occurred.
It could possibly be memory related, running low or fragmented memory.
What happens if you save your project, reboot the computer and continue on?
Thanks for the reply. The message would stop the song but I can just restart the song again instantly without any problems or having to reboot. My CPU is showing only 10% usage (about 1 to 2 bars) and HD has no bars showing so I didn't think it is memory related. I am running Logic on 64 bit since I have 8GB so I thought it would be sufficient. The message is random and it is just a few times during the day but it is annoying when it comes up. It just happens sometimes even in the same song and during the same parts of the song even when i am looping.
The only other thing I can think of would be a project that is corrupted or beginning to become corrupt.. make sure you have more than one copy of the project file available in case you need to go back to an earlier version.
CPU and HD use being low doesn't mean the memory is not fragmented, but that doesn't sound like the problem.