[Jaws]

I have several (expensive!) multilingual dictionaries in .mobi format. The one consistent problem is that they're not converting to .epub in Calibre 4.10.1 (or prior versions back to 3.something). Unfortunately, that's where the consistency ends. The conversion "fails"; scrolling down the details, one sometimes finds a timeout, sometimes a memory failure, sometimes a Python variable out of range. So I'm not sure that any kind of an error dump would help.

I don't have this difficulty with other reference works from the same publisher(s) (mainly Oxford UP, but also a couple of German publishers). The one difference for multilingual dictionaries is that they tend to use a lot of unusual-for-ebooks Unicode characters (primarily, but not exclusively, as pronunciation aids), plus they tend to be quite large files (upward of 10mb with minimal illustrations).

Has anyone else encountered this problem? Is there, perhaps, a workaround? It's probably unusual enough to not justify much diving into the code; it may also just reflect a memory or other limitation in Python that can't really be solved.