XLIFF Converter not importing all fields or nothing at all?

We regularly have troubles with the XLIFF Converter. Sometimes non of the segments are imported again. But there is no error message.

Recently we had 3 situations where a few segments were not imported. 

Now I have 2 generated word files, one which works and one that doesn't. But I can't really find any difference between the two. 

Are there any internal things that the tool checks before importing?

WordFiles.zip