Created attachment 140634 [details]
Screenshot with missing translation
In reminder window, the caption "Dismiss All" is not translated into German.
This string can be translated.
But 5.13.3 is very old (last version is 5.18.0).
So better to test with new version.
Fixed in newer versions. See bug 432820.
*** This bug has been marked as a duplicate of bug 432820 ***