Originally posted by k0zmo
Mate can you please help me I signed into psn but it signed me out and said You cannot sign in using another users sign in ID (email address)
Hmm that's odd. Uhg well now that I am aware you were using a vpn that could be the possible culprit. You may have not had it setup properly. which could have caused conflict in not allowing you to sign in.
Retry to set the cid and try signin in without the vpn and see what happens.