I upgraded today to UP6. Everything went smoothly. My issue is Cinnamon, it fails to load properly. I have uninstalled/reinstalled Cinnamon, including mint-meta-debian-cinnamon,mint-debian-core, and uninstalled mint-x-themes.
When I run the command "version --cinnamon", it does report 1.6.7. Cinnamon settings are in menu but any changes I make,nothing happens.
Under processes, no Cinnamon is found.
I have restarted Cinnamon a few times.
When I log in and choose Cinnamon 2d, that works,,,,When I choose Cinnamon or System default ,that is where the problem is.
I am running conky and AWN , LMDE 64
Hope thats enough info