Well... hmm.... I'm really sorry, but I didn't get anything.

The last half hour I spent with testing it again. I tried to change a couple of strings but always got the message that there are errors in the file and that I should run "msgfmt -c".
I did that and changed the header of the file to remove some warnings, but I still got the same error from transifex. After that I uploaded the German translation as Swedish translations. The upload went without problems, but then while translating I got the same error again. I tried the same with the French translation but with the same outcome.

After some more tests it turned out that I was making a mistake in my tests. I always translated the first string which is "New Note %i" to the string "Test". This triggers an error because I did not add the "%i" to the translated string. The problem is, that the transifex error message was totally generic without giving any hint what's wrong.

After including the "%i" everything worked again.

I'm not sure that this has anything to do with your problem, but I thought it's worth mentioning.

The Swedish translation is now mostly French with some test strings. Please try again to change something (one or two strings should be enough).

I really hope we get it working for you and I think we found something where transifex.net really needs to do better.