Due to invalid xliff from Across there is a check in the xliff import from Across, that checks, if there is text outside of mrk-tags of mtype "seg" inside of seg-source or target tags.

If this is the case the import stops.

This behavior is ok, as long as there really is text, yet if the content is only tags plus white-space, the import should pass. All white-space characters (including nbsp) should be recognized as white-space.