Possibly old app changed association directly. It it's done, association is reset. https://stackoverflow.com/questions/17946282/whats-the-hash-in-hkcu-software

Possibly old app changed association directly. It it's done, association is reset. https://stackoverflow.com/questions/17946282/whats-the-hash-in-hkcu-software-microsoft-windows-currentversion-explorer-filee https://stackoverflow.com/questions/17946282/whats-the-hash-...