Hi, I am so fresh of Windoze you can smell it on me LOL 
Please be so kind to assist with double clicking on PDF or Picture etc… to open it, at the moment I must right click and select open with and I have no idea how to fix it in POP OS.
I do not have many issues with POP OS after watching Jay’s YouTube video at all, everything just worked, but I think I broke the double click some how.
Greets
Jason
Are you giving it enough time to open? What applications have you installed for PDF and images. What apps are you clicking on to “open with”.
I bet there’s a setting for actions like “Double-click to open files.” or something like that?
Hi BigBunny, Thank you for taking the time to assist.
I do have Apps for TxT and PDF and also images and I can right click and select from popup menu, open with, those Aps, with no problem at all.
Problem is if I just double left click on any TXT PDF or image file it does nothing.
I also noticed that in Thunderbird no attachments can be opened or even set from thunderbird, it does not show my Apps to open specific Aps, that are installed.
I have to save the files (PDF) attached to the emails to disk first, then right click on them and select the correct App to open them.
Thanks again kind people for your time.
Can I ask what version of POP OS you are running, and I assume that you are running the default Gnome desktop with POP OS mods? Was this a fresh install on a clean disk or have you installed over a previous versions? I am currently running POP OS 20.04 so have installed Gnome Tweaks, that I would recommend that you do, but if you are on 21.04 then much of that if not all is already installed by default. Jay has done a good video on 21.04 that I would suggest you refer to if you have not already seen if on that version.
One other thing did this ever work or have you installed an app, etc that could have had an affect? If so remove that first and test. Some apps clash and though not as bad as Windows used to be still happens occasionally.
From memory with Gnome others have had this type of issues in Ubuntu and similar have sometimes found this is being caused by Nautilus that relies on GTK. What they have had to do is remove and reinstall Nautilus from the terminal. If you go down this line don’t forget to purge Nautilus so all remnants are removed before the re-install. However as POP OS tweaks it it is unlikely to be exactly the same so maybe a better solution would be back up everything that you need and reinstall POP OS. I am thinking here of the fact that you have only recently come over to Linux so the easiest way to resolve your current issue.
However before you do this go to your settings and check that everything is as it should be and if not sure turn them off/on and see what the result is before reverting. If on version 20.04 and you have Google Tweaks installed then open it up and have a look to see what happens when you make adjustments to anything that is looks like it may have an affect.
Not a solution but just some things to try to resolve your issue.