Most likely an error in your airport. The message says there are error details in Couatl.err file, please post its content, because it might help us understanding what's wrong with the scenery. As explained many times already in the forum, whenever you report any problem, always include the following information:
- The Airport used (if it's not default, clearly identify the addon scenery)
- The Gate used
- The Airplane used
- If you see a message prompting you to check the contents of the Couatl.err file, the content of that file.
