[KevinH]

The issues you are seeing are not well explained or described. Please provide complete and detailed instructions and even a sample epub, so that others can recreate exactly what issues you are seeing.

The only real difference in Sigil itself on Windows between 0.9.11 and 0.9.12 is a single character of python code that is only invoked under very special circumstances under user control in css sheets with fontface settings.

So if you are seeing any differences between the official 0.9.11 and official 0.9.12 versions on Sigil on Windows, then those differences are being caused by something else specific to your system.

I strongly recommend re-downloading the official Sigil 0.9.12 version from github releases (and no where else), validating the checksum to verify a good download, and then installing it.

Then carefully report any issues you see giving step by step directions on how to recreate the issue and people here can try to recreate it and track down the underlying issue.