After attempting to create a CSR from template we are receiving the following error in the Stat Windows Client:

When a Stat user tries to create a CSR from template without having any template created and having only one domain configured, Stat does not throws the ideal error message.
However, users who have more than one domain configured in Stat, they do get the ideal message of "You have not defined a CSR Template for this Service Domain".
Check how main Domains the user has access to. Most probably that user only has one domain configured.
Then, check if the user has any template created. If not, create the template and you should not get the error message anymore.