When trying to open display preferences in system preferences i get prompted with the following error: "preferences error. could not load displays preference pane." Does anyone know why this is happening? PS: it's the only pane that's causing problems
Sounds like that pref pane file is corrupted. Just command-r to recovery and click reinstall OS X and it will replace it. Backup first just to be safe, but a simple reinstall like this without erasing anything will not delete your data.
I have exactly the same problem, straight after upgrading. There were no problems with the upgrade, except it taking ages to run.