Solved ePUB File Association Broken - Baffled

[pjd]

I have had the EPUB file type associated with 2 programs for a couple of years - Sigil and the Calibre's Ebook-Reader. Sometime in the last day or two I've lost the Calibre Ebook-Reader association

When I use the OpenWith context menu it only lists Sigil. So I browse to the Calibre 2 folder in Program Files and select ebook-viewer.exe - nothing happens.

Then I recall that I have an EPUB extension in firefox, so I browse to the Firefox folder and select firefox.exe - voila its there - right next to Sigil

I can open EPUB files from within Calibre itself via its View function, which fires up - ebook-reader.exe,
I can open EPUB files with ebook-reader.exe via Calibre's Open With plugin,
I can open an EPUB file by dropping it onto the ebook-viewer.exe file, or a shortcut to it

So I am assuming this is a Windows issue and not a Calibre issue

A one stage in 'trying to fix it' I got the error message you see in first attachment. I've also attached an image of the entry for EPUB in HKCR - which looks a bit sparse to me - where are the associations to Firefox and Sigil that I see in the third screen shot.

I did System Restores to Friday, Thursday and Wednesday mornings - made not a scrap of difference, almost certain it was OK on Thursday. And I've un-installed and re-installed Calibre.

PJD

Addenda - I think the error message is a Python message, Calibre is written in Python - still baffled

 

[pjd]

Solved - did something I tell others not to do - ran a registry clean with CCleaner

pjd