- Edited
brado If you still have k-lite installed.
IN CASE this ffs up your other video players, you can restore your backup you make at the start, point 1. Actually, might even consider making a windows restore point for good measure. That way you can also undo point 3. The codec tool backup might not have that saved.
go to start, type codec tweak tool
In Media Foundation nothing should be checked after reset. Double check.
Restart all VR/video/browser software you might have open. Test if playback in SLR/Deo is fixed.
If still not fixed, open codec tool again, in lower left go to Preferred decoders.
switch all h.264 h.265 mp4/mpg4 to LAV, both 32 & 64 bit.
Audio you can leave; Unless it turns out it's an audio codec issue. But first try without changing audio settings. All SLR videos use AAC. Pretty much everything media supports it.