Hi, just had one of those instances where I added a new cover and the next time I went to use the plugin, there was a message about configuration file corruption. I'd previously thought this was tied to using hyphens in the names (and stopped using them, which seemed to stop the corruption from occurring until fairly recently), but this case involved no hyphens, so, as to what happened:
1) Had two epubs selected. Clicked on Generate Cover plugin.
2) Plug-in was on a cover "Bucky Steve 7" I'd created some time ago and had used earlier today to add a cover to a new book in an ongoing series. Cover was set as 500x700 dimensions using a non-stretched image also named "Bucky Steve 7", contents order of title, image, author, series, all text centred
3) On the settings page, clicked "Add Setting" and from that profile created a new one named "Botanical Diaries"
4) Clicked "Add Image To This List" and imported an image also named "Botanical Diaries"
5) On the "Dimensions" tab changed to a stretched image
6) On the "Contents" tab changed order of elements to title, author, image, series
7) On the "Fonts" tab changed the fill colour
8) Changed title and author to right-aligned
9) On the "Dimension" tab I decreased the bottom, left and right margins. NOTE - previously reported error with changes to left margin incorrectly affecting starting placement of right-aligned text is still is effect

10) On the "Fonts" tab adjusted sizes of font
11) Saved and applied the cover
12) Decided to further tweak the cover, clicked on "Generate Cover", corruption error message appeared - details reported that "Bucky Steve 7" had incorrect internal name of "Botanical Diaries" and was being fixed
13) New cover "Botanical Diaries" is still present and looks correct. Previous cover of "Bucky Steve 7" is gone from list entirely and will need to be recreated.