A .warning file extension is related to VIR Validator software developed by NASA. A *.warning file stores results.
WARNING file extension - NASA VIR Validator results
What is warning file? How to open warning files?
File type specification:
The warning file extension is associated with the VIRV (VIR Validator) a specialized software developed by NASA that is used to check Spacecraft Activity Sequence Files (*.sasf file extension).
The warning file stores some kind of results created after check of *.sasf file.