EditorUtility.UnloadUnusedAssetsImmediate() crashes 5.3.2f1

I says nothing, but drops out completely.
I've just upgraded to the latest. This call worked fine for all other version, and it's been in my code for ages.
Am I missing something about this? It is useful for freeing up editor memory.

Thanks.
Dave.

 

Thanks for the reply, I suspect it's because I'm calling it in the wrong place, here's the error I get now, it causes a 'fatal error.' Is this often seen?