How do I resolve it?
Thanks for coming back so quickly. The programme was working fine until I messed up copying plugins into the Plug in directory. I lost confidence and then uninstalled Photoshop, but inadvertently reloaded beta version of CS6. I then unistalled that and then downloaded and installed a new version from the Creative Cloud, and now need to press the OK button 21 times whenever I load up PS.
I am running windows 7 and PScs6 64bit.
Following your reply, I have tried what you suggested but it did not change anything.
Have you any further suggestions?
You caused the problem by copying plug-ins supplied with an older version of Photoshop. You're not the first. You can't mix Adobe plug-ins from an older version of Photsohop into the new version. 3rd party plug-ins are generally okay.
Uninstalling does not remove plug-ins. You have to clear out the plug-ins folder manually.