I called for help for you. What account are you having problems with? Mozilla has several.

Thanks a lot for the letter. Actually I don't quite understand what are you talking about. When you open the Mozilla browser you are invited to create an account. This is the type of account I have. It could be described as a usual pair of login, which is just an email address and a password which I prescribe do this login. That's it. I have a PC and iPhone, which are connected to that account ( I use it to sync my Mozilla bookmarks). But I can't to link one more device - my iPad. And all attempts to login to existing account in Mozilla finishes with invalid login or password message. And proposition to reset the password. When I tap "send a link to reset a password ", no link is sent to my email. That's all I can say. Sorry.

Ahh, you are talking about your sync account. Sync allows you to share data between devices.

OK. So, what should I do connect this devic? At the moment I've just add another iPad mini. And it synced easily. I don't understand what goes wrong with my big iPad...

It's kind of rediculous, but it happened somehow. Honestly - don't know why. Just happened. Miracle. Thank you once again for support.

All I did was send out for help. Could have been a system problem that was fixed.