APTSAVEFTX — Creating .ftx Files to Troubleshoot Formatting
Set the APTSAVEFTX environment variable to yes to save formatting information as .ftx files (binary version of FOSI files) in the aptcache\ftxCacheDir directory. PTC Technical Support can use these files to troubleshoot formatting errors.
Open the System Properties option from the Control Panel. Type APTSAVEFTX in the Variable field and yes in the Value field on the Environment tab. Then select Set.