Q: PFE used to work but now it won't compile a flight plan even though the Compile button works and is not greyed out.
A: A few things to check in ProFlight Settings... please ensure you have your Cruise Altitude set to at least the same altitude as that in your flight plan... also ensure the Center Altitude is not too low (you may need to experiment with this one but tests have shown it can be too low which can prevent PF compiling the flight plan.... the default is 14,500)... also make sure the Center altitude is lower than the cruise altitude... if your regional currency settings are set to a comma rather than a decimal character that can also prevent PF from compiling the ADV flight file. If all else fails please try setting your regional settings to English just to see if that cure the problem.