joeblowma

All I can say for certain is it used to work fine, maybe it was the 5.x upgrade that lost it? Definitely a great idea as a workaround, for the reason you state I might just wind up doing the same - multiple files at once. Thanks for sharing!

It started for me after updating to windows 10 latest release from 1909 and initially I thought it was a problem that would work itself out somewhere along the way. Finally got sick of having to use the "open with other app" dialog today and did a dig into it, and came up with an interesting fix. After delving into keys for .jpg, .bmp and others and finding paintdotnet.exe already there I grew confused, until I stumbled into this answer on superuser: https://superuser.com/questions/1199648/strange-open-with-list-inconsistent-with-registry/1256482#1256482 The .ApplicationCompany key is missing for paintdotnet.exe in the mui cache, and creating it there got paint.net showing up in the open with context but it will eventually fade whenever windows decides to refresh this cache. From there I got out a resource hacker and looked into it, and there is no CompanyName specified in the version info resource which is what derives the mui cache keys. I don't know if this was removed recently, but for whatever reason windows 10 doesn't like it being absent and hopefully there aren't about to be a bunch of people with a cache refresh that breaks open with for them.