So on my zombies map everything was working fine until I added my second floor. The zombies go up the stairs and step onto the 2nd floor platform I have made, but they eventually just stop for some reason, even though its a perfectly straight platform and it looks like the zombies should definately be able to get across it. Its not like they have to make a massive jump or anything, its just even ground.

So what the zombies do is just stop and do the 'confused' animatiion, where they do not move. I'm hoping this is something simple I'm just being stupid and missing.

Any help is appreciated. Cheers

Expand your navmesh to surround your new area.

can someone help me with navmeshes.  I'm having the same exact problem and your the only other person having it and I really need your help because i've asked EVERYWHERE and no one has given me a reply and I just want to finish my map!!

not sure myself here however a navmesh is a trigger (according to radiant), I think the  reply that AllOutWar  gave he ment a navvolume I'm having the exact same issue they walk up the stairs but as soon as i walk onto lvl 2 they do the confused animation i can coax them onto it by letting them hit me they stumble onto lvl 2 and follow me no problem but they just wont go from stairs to lvl 2 them self's I've not set up separate nav volumes for each area just yet im using 1 large covering my whole map i want to  get all the bugs worked out before i start making zones with individual nav volumes

any help from an expert would be much appreciated   

Post a screenshot of the problem area.