This is very minor, but anyway: the small buttons in the lower right corner have no text, no icon and no tool tip, so it's not possible to know what they do unless you click on them.
Oops, more than a blemish it seems, do NOT click the rightmost buttons, that seems to clear the folder names in the list boxes, and now I cannot even start the Mod manager anymore, it just crashes with a runtime error: Faulting application modmgr.exe, version 0.9.3.0, faulting module modmgr.exe, version 0.9.3.0, fault address 0x00075206. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Solution: HKEY_CURRENT_USER\Software\Image Space Incorporated\rFactor2 Mod Manager\Working Dir\File1 was blank and caused the crash. Setting it to point to the installation folder cured the crash. Not sure why those unmarked buttons would reset info which is needed to start the program again?
Definitely something's going on, initially it appeared to just remove the current working directory from the drop down list without any observed side effects. It wasn't until I removed all the entries (multiple installs again ) that I got it to misbehave. Trouble is it doesn't seem to be consistent, sometimes after clicking that X button to remove the entry when I try to exit ModManager sometimes it crashes and sometimes it doesn't. This seems to lead to 3 different things happening in that registry key. One is that there are no file strings and ModManager opens no problem. Two the 'File1' is blank and ModManager crashes when opening it. Three the 'File1' string contains random characters, ModManager opens and the random characters can be seen in the ModManager Working Directory list!
