Invalid namespace URI when converting certain CHM files

[natemiller82]

I know .chm files are sometimes a little finicky; I've gotten most of mine converted to epub, but a number of them will not convert to any format (including .html via calibre). They all have the same error:

ValueError: Invalid namespace URI u'3D"urn:schemas-microsoft-com:vml"'

Is there any way to fix this, i.e. ignoring this specific line in the conversion?

I've converted to HTML with 3rd party software, but this creates a directory with one html and lots of .mht files; I'm not sure how to use those to make an epub.

[kovidgoyal]

Use the search and replace feature to replace 3D"urn:schemas-microsoft-com:vml" with something that is not invalid, like xxx