The slow motion doesn't work. There is a speed counter in my right corner and it even changes, when i press < or >. But the replay itself stays on normal speed. I waited for all replays i was trying to slow down to fully load, i waited for them to play, i tried every basic thing i could try. Got any leads what that might be?

have you had the replay finish all the way? if the slow motion counter is grey, it wont affect it, only when it turns black then you can slow down or speed up.

Yeah, i've loaded it (not quickloaded, exactly loaded) and watched all the way. The counter just doesnt turn black for me, never.

Most likely to be a glitch, which version are you using? Steam or Standalone?

Steam, 5.1

Try using the standalone version http://www.toribash.com/download.php