Account Details could not be opened because of an error connecting to iCloud.

Hi All

When I boot my Macbook Pro running OS X 10.10.4 Yosemite I get a box asking for my iCloud password but I get the following error every tim I enter my correct Apple ID password.

Account Details could not be opened because of an error connecting to iCloud.

I can acess my Apple ID account via the web ok and I presume the iCloud password is the same password as my Apple ID password?

Everything seems to be working ok as far as I can determine but its annoying to be asked for a password that is never accepted.

Any help appreciated.

James