Also had this happen to me again at one of my installation sites. Lost all my midi settings and unable to reload them from the backup. Not even the default midi presets are available in the dropdown menu.
I finally had a chance to collect the documents folder and sending you a link.
I have tried to uninstall and reinstall with the same result. When I tried to zip the folder, I received this message. I had to rename the file "45" in order to zip it.
I notice that there are 2x "45degree" presets for "lines" on all my machines.