Creative cloud won't sign in

Using CC on Windows 8.1, 64-bit machine. Also have it on a Mac within terms of agreement.

Trying to sign in using Updater or CC App, but it won't let me. Each time I sign in, it comes up with the message 'You've been signed out'. Tried multiple times. Have changed password and tried again, but to no avail.

When opening Updater or Creative Cloud App, no prompt given to update

Can sign into my Adobe account okay.

Have run IMSLibReplacer.exe as suggested here -http://helpx.adobe.com/creative-cloud/kb/unable-login-creative-cloud-2 48.html

This gives a succession of fails on rename and copy commands with error as 5 on all of them.

Any ideas?