My apple id does not accept my password on my macbook

I can log in my apple id on my iphone and ipad, but when I try to do it on my macbook pro it doesn't work. I've had this problem for more than a month and on the support page they weren't able to help me. Because of this I can't log in on my icloud or synch my phone, it just says "Action could not be completed. Try again". I've tried changing my mail or password, but didn't work either.

Replies

You can't log in to iTunes Connect? Member Center? ....where?