Compile to Mobi problems

Version: 2.9.9.13 Beta (1129554) 64-bit - 04 Dec 2020

I am unable to publish to mobi. It runs through compile process and even if I uncheck the “Open compiled document in default application” option in the Options (gearwheel) tab of the compile dialog, it tries to install Kindle Previewer even though it is already installed. I then get an error message with no details. Kindle Previewer 3 was updated to version 3.48.

I have tried compiling with no front matter or image but it must be something to do with the above.

So I just compiled a project in RC13 to the MOBI target, using the previously installed Kindle Previewer, and it created the .mobi file as requested. When I went to open the file, however, the actual Kindle application – not Previewer – handled the file request and automatically installed an update. You might want to ensure that you have the latest version of the Kindle app downloaded (or remove it entirely and ensure that Previewer is the default app for handling .mobi files) to eliminate that potential conflict.

If you uncheck that option, does Scrivener create the .mobi file for you and can you then manually open it in your desired application?

I had the mobi issue with the former RC. Now with RC 13 it works just fine.
And I have a vry old KindleGen installed