I am having a curious problem lately - hitting Reimport Mesh does not work. I get the popup saying the reimport was successful, but the mesh itself does not update. Am I missing something obvious, or is this an actual bug? It’s happening both in 4.10 and 4.11 for me.
I also do not re-import does not work.
I’ve had this happen a couple of times for various reasons. One time I had been exporting the asset to the right folder… In the wrong project 
so check out where you are putting the new file first.
Another time I genuinely couldn’t figure out what was wrong, so I just deleted the asset from the content browser and reimported it.
Really that’s the best thing to do, because honestly Unreal reimports automatically if the fbx file is changed. So if that’s not happening something is wrong that will likely take longer to fix than it would to just delete the asset and bring it back in.
Of course, if you choose to do that you will have to place the mesh again wherever it was in your map, so… Extra work lol