I'm in for the same problem. Occurred after installing Aerosoft's Toulouse.
The original problem was caused by an empty line in the "disable_airports" line of the couatladdons.ini, while if your problem is caused by the installation of the Aerosoft's Toulouse, it's fairly obvious you are NOT having the same problem. And besides, we already fixe the problem in the most current version of Couatl.exe which is online since a week already so, the problem reported here can't happen anymore, if using the most current version.
Since your problem is not the same as discussed here, so you should really open a new thread, describing your problem, otherwise it will become very confusing to keep two threads opened discussing entirely different issues at the same time.