Link button not working in editor after upgrade

I have done 6 upgrades (all to 2.5.1) from various versions from 2.0 to 2.3 in the last 2 days, the only problem I have yet to solve is:
The link window is blank when it pops up, and so is the add image window. I have tried deactivating ALL plugins and it is still blank. I have reloaded all the files, I have cleared cache’s done everything short of putting my fist through my computer screen, if I thought it would help I’d do that too….

Any help on this would be greatly appreciated.