Does tht user have read access to the SQL database? How about creating client task and generating other queries logging into the same a/c? Also check if you have allowed the user for DLPWCS service. When you install DLPWCS if you have not chosen something like "everyone" and "domain users" - that might be creating some issues?
What version of DLP you have - suppose DLP 3.0?
We are running DLP 3.0. There is no DLPWCS service. Maybe you mean DLPWCF. Both accounts are member of a group which has access to DLPWCF.
I have given the two user access to the server/datebase and supplied them the role DB_Datareader. When i perform a test, i get the following message:
EXECUTE permission denied on object DLP_sp_PolicyInfo, database EPODB_SERVER, schema dbo
I solved the problem. I created a new role (CREATE ROLE db_executor) and granted the role execute rights (GRANT EXECUTE TO db_executor). After that i granted my account the db-executor role.