Plex is not working - Conversion failed. A required codec could not be found or failed to install.
I already tried getting Plex to work like a month ago, but even with some help from Discord mods, it just didn't work. I was always getting same error; Conversion failed, transcoder crashed or failed to start up. Even when I tried to create Plex Media Server on my laptop, it gave me the same error so I figured something must have been wrong with my network settings, but I already tried opening ports and there is nothing else I can try to troubleshoot.
The only file that plays is a documentary in .mp4 but only if quality is set to Original. If I try to transcode it to 720p lower bitrate or any other setting that isn't Original, it says "Conversion failed. A required codec could not be found or failed to install".
-using default and custom directory's
-reinstalling several times
-installing Plex Media Server on different computer
-disabling firewall and opening all listed ports
-manually copying .dll codecs in \AppData\Local\Plex Media Server\Codecs folder, but after I do that, I get "Conversion failed. The transcoder crashed or failed to start up.
I even pressed page 2 on Google search when I was desperate enough to find solution to this problem. It just doesn't want to work.
I am trying to get Plex to work again because I got email with redeemable code for 1 month of Plex cloud, so this should be the best time to try Plex, if only it would work for me. Does anyone have any other suggestion I should try? I really want to use Plex, but it just doesn't let me.