I had an issue in 4.8 where the animations i use to import were no longer importing. The help support i was using recommend i grab this change and it worked:
https://github.com/EpicGames/UnrealEngine/commit/cad5083bdb21830350a3447fb287b3107691e862
They have asked me to post to answerHub since they below my sample data, attached below, may be due to a bad export.