A few days ago I was playing the game in someone's server, he wasn't modding either. Near the end of a 5-hour session with him I was suddenly unable to see spotting outlines from myself or others, and all highlights from tracks/blood trails/etc were also missing. I can still interact with them all and spot, but the game is literally impossible to play without the highlighting working (unless all of my shots are heart shots). I'm red/green colorblind so even if the game showed an actual trail of blood instead of the splotches I still wouldn't be able to see.
I checked the settings to make sure nothing had changed, but the issue is still there both solo and in other players' sessions. I have tried resetting settings to default and even re-installing the game from scratch. Issue is still there. Any idea what to do?