Bug Can't import any 3D models (Unity 5.6.2)

I get this error in the console when I try to import a 3D model (I tried .blend, .fbx, and .dae):

Failed loading fbx importer
​

The following shows up in the editor log file:

Hashing assets ... 0.021 seconds
file open: 0.000 seconds (2 files)
file read: 0.020 seconds (2.622 MB)
hash: 0.002 seconds
Updating Assets/Models/Test.fbx - GUID: e23fee4bee9168f4ebd6e29d37572384...
Failed loading fbx importer
(Filename: /home/builduser/buildslave/unity/build/Editor/Src/AssetPipeline/FBXImporter.cpp Line: 513)

done. [Time: 78.220001 ms]
Refreshing native plugins compatible for Editor in 0.40 ms, found 1 plugins.
Preloading 0 native plugins for Editor in 0.00 ms.

----- Total AssetImport time: 0.140514s, AssetImport time: 0.094827s, Asset hashing: 0.020761s [2.6 MB, 126.297424 mb/s]

Refresh: detecting if any assets need to be imported or removed ... Refresh: elapses 0.025307 seconds (Nothing changed)​

 

I can't replicate that behavior here - corrupted installation?

 

It took a system restart (not just Unity), but it's working now.