Are you using a Mesh supported viewer and still having issues? Your mesh house vanished? Seeing people sporting this lovely look?

Missing Mesh by Renoobed (aka pancake), on Flickr
If this happens to you don’t panic. There are a few solutions that can help.
1) Make sure basic shaders are enabled. I know for some with older computers this will kill their FPS and SL will become difficult, but on some of the viewers you will not see mesh if your shaders are not on.
2) Go to Advanced – Debug Settings and find MeshMaxConcurrentRequests and increase this. Your default is probably 32 and you want to double this to at least 64. I’ve heard of one person who set it to 300, but I keep mine at 150 and haven’t had a problem since. I’m no technical expert, but my understanding is your viewer’s ability to see mesh can get “full”, like a cache of sorts I guess. As more and more mesh hits the grid, the default MeshMaxConcurrentRequests is proving to be way too small to handle what we see and sooner or later our viewer just stops showing us mesh. Increasing this helped me a lot.
3) Relog.
That seems to fix it in *most* cases. One thing to note, Exodus seems to be having a notoriously hard time with this and these tips probably won't work for you.