In older versions, files ending in .key were correctly identified as SSL keys and had a bank safe icon and opened with a certificate program.
After updating to Mint 18.1, they now have Powerpoint icons and try to open with Open Office. The Kind field in Thunar reads, "Apple Keynote 5 Presentation".
How do I fix this? I know I can change the "open with" but it's the type detection that's wrong, not the program it opens with.