Not to worry! What happened is that you switched to what we call "Power User View". It is an alternative Plesk interface more suited to managing small numbers of domains. To get back to managing your customers and resellers, fill in the fields (just type in any user name and generate a password automatically) and click OK - a subscription will be created for you, and you will be able to log in. Afterwards, you can switch back to the "Service Provider View" - just click Change View in the bottom left part of the screen and select the corresponding option. All your customers and their domains will be there )