Which method are you using to connect to the database (Service Acount, Impersonate, etc.)? Is the database on a different server than the K2 database? I have a few suggestions depending on the above:
Make sure the K2 service account has access to the database in question
Try toggling "Use Native SQL Execution", particularly if it is on a different SQL Server
Hello @MoMapaela,
I actually created an article about this, that I will link below to make sure you perform the necessary checks to get the Service Instance to work with SQL. There are checks that are needed to be made when creating a Service Instance from SQL, from the proper permissions within SQL to making sure you select the right "Authentication Mode".
How to Create SQL Service Instance and SmartObject:
http://community.k2.com/t5/General/How-to-Create-Custom-SQL-Service-Instance-SmartObject/m-p/103094
Thanks,
Michael
Thank you everyone for their solutions - I managed to get it working.
Would you mind sharing what the solution was? This is a common problem, it would be good to have the solution documented here for future generations of K2 developers :)