Thank you very much for your hard work on this Plugin!
Since I updated the version to 1.11.0 I have the same issue with every conversion, regardless which pre-format I use.
calibre, version 3.9.0
FEHLER: KFX conversion failed: <p><b>Cannot convert Der Engelsturm</b><br><br><b>Kindle Previewer error:</b> Error(EpubProcessor):E141214: Unable to execute the binary: .\bin\yjhtmlcleanerapp</p>