In order for a SoloBot to auto-login and execute a Process, it needs the "Console Session" to be available.
The console session is occupied when a user is normally (not via RDP) signed in to the machine.
Hence, in order for the issue to be resolved, verify that the machine's "Console Session" is available.
In case it is not, the corresponding user will need to sign out.
Note that the console session's availability can be checked via the "query session" cmd command on the SoloBot machine.