Can't keep file associations

I'm pretty sure this is a 1809 shenanigan but I'll post it anyway.
I just made a clean install of Win10 and since the reinstall I can't make the file associations "stick". When I try to open a file that has no association, I can select the program I want to open it with, but even if I mark the "always use" checkbox, the association won't happen. Next time I have to choose the program once again if I want to open that file.
What is really weird is that I can change the default apps, but I can't set the defaults by app, because some of the apps simply don't show up in the list (Notepad++, Corel Photoimact etc.).
I can't set the default by file type either, because the file type isn't in the list. I can work around this problem by using this method so I can see the extension in the list, but even if I choose an associated program, nothing happens. And I can't choose any other program than the defaults unless I already opened that extension once before...

Any ideas what to do?

i have a similar problem with images i added the .re file to bring back photo viewer, click an image click more apps, highlite vw, tick the box, the image opens in vw. the next time i have to go through the steps all over again. now videos, text docs, etc all keep what i set. it's just images. now i noticed that i don't have the checkbox.

dalchina said:

Seems Notepad++ doesn't register itself to handle e.g. txt files- doesn't appear in list of available apps even using Open With/More Apps for txt and I'm using 1709 - so issues about Notepad++ probably aren't unique to 1809

Apps will only show in the list if the author has configured them to write to the registry as capable of handling a particular file type.

notepad++ never does you have to go into it's settings and do. aw that last part explains a lot.

Before 1809 I could associate files with Notepad++. I would gladly revert to 1709, except that with a clean install it is not possible...

dalchina said:

If Windows' GUI now won't let you, you can still do that with 3rd party tools.




- just for example. However this is not something you'd want to do often.

I fully agree, I already have this tool, but i gave up re-linking all my defaults after the first 20 odd "corrections" And thats just getting my basic programs linked...

dalchina said:

If Windows' GUI now won't let you, you can still do that with 3rd party tools. just for example. However this is not something you'd want to do often.

why when filetypesman is a great app

IAmNoOne said:

why when filetypesman is a great app

Because in my opinion it's great for a when a single program has issues with file types, and this is a very good and quick fix.
But with multiple issues, it can take a long time to fix or correct as each line is a manual input.