Since somewhere from the start of Nest of Vipers, my main quest markers aren’t showing anymore…and my last save they seem to be working right on is from a week ago (about 10 hours+ ago…), hoping that using online maps to find everything and finishing the quest re-establishes the Main Quest markers again on my map (side/activities showing fine), otherwise will have to set the game aside, which would literally make me cry tears of Henry sorrow 
There is no quest marker on that quest! Just read your quest log…
Sorry but this is incorrect: I reloaded an older save and the quest marker for the woodcutters camp is there, and with the same objectives in a far later save game, they are gone…I managed to complete the quest now, but the shield didn’t come back until I had to go to Sir Radzig again, but eventually worked.
Also bugged out on Runt big time with a black screen, both bugs reported however.
Depending on your decisions from the previous main quest you will either know the location of the enemy camp in Pribyslavitz or you will have to find it by following received hints. Regardless of that the best place to start your journey to the camp is the woodcutters’ camp located north Talmberg.
Runt scene was bugged me too… I have reloading an earlier saved game and it fixed - somehow.