Ascello, if you using a vendor version of Calibre and FFF, it may be installed weirdly. Some vendors have very definite ideas of how they think Python apps should be installed. From what you describe, I think that includes your install.
I don't know anything about those versions and I don't directly support them.
I only support Calibre as installed from
https://calibre-ebook.com/download and FFF plugin as installed from
https://www.mobileread.com/forums/sh...d.php?t=259221 either directly or through Calibre itself.
And FYI, personal.ini isn't actually a file in the plugin version, it's stored in the library database.