Try to select the "Restart Couatl and rebuild the airport cache" option from the Couatl Settings menu. Be sure you wait for the cache regeneration to complete successfully.
Configuring the antivirus to exclude the whole flight sim folder from scanning will speed up the cache regeneration a lot, maybe it's just proceeding very slowly because of the antivirus, so you cannot see any airport until the process is done. On a normal system it shouldn't take more than 20-30 seconds ( at most ), but with the antivirus enabled and not properly configured, it might take several minutes.