That error looked like a similar error that happened on P3D up to a certain version, then it was fixed by LM, which was caused by a bug in the sim which reported that error (caused by ANOTHER Simconnect application), into the wrong "innocent" application, which is KLAX in this case so, we get errors that looked like were happening in our software, but were caused by other addons and were "leaking" to us, because of this bug, which has been fixed.
It's *possible* the bug is still there in FSX, and I see there are some objects with corrupted names which don't belong to KLAX in the error log, so it really seems another application that is creating Simobjects has caused this, since we surely don't try to create them.
And yes, of course, by resetting Couatl.exe, you cleared up the error, because after a reset it register itself on Simconnect with a different ID so, possibly, the rouge application that it's causing this, is leaking into another client.