There's several reasons this error can occur. It would be best to open a ticket or call into support so we can go over this together.
Some of the reasons can be:
The username/password is incorrect.
The domain format is not working for the system. In the credentials section there is a field for the domain name. Entering the domain name here typically works, but sometimes the system wants the domain with the username field like "domain\username" and then leave the domain name field blank.
The Event Monitor (AMEM.exe or BPAEM.exe) is not running or running under a user that is in a Disconnected state. A disconnected state is caused when a user logs in through Remote Desktop and then closes the Remote Desktop session without completely logging out.
Something in the logon process is failing. Automate needs to send a CTRL+ALT+DEL at the logon screen. This may not be happening. It may need to get past a legal notice/warning. It may be getting stuck on this. It will then need to send the credentials as well. There's also a chance that all this works, but takes longer to login than Automate is waiting for. We can adjust this delay if needed.
Like I said, it would be best to contact us for a support session to review this together on your system.