Import Metadata in OBIEE throws TNS error

I was trying to import metadata for a table that had some columns change within the OBIEE repository using the Administration tool for The connection pool I was using came from OBIA and used repository variables for it’s data source name and user name fields. These were set to VALUEOF(OLAP_DSN) and VALUEOF(OLAP_USER) respectively. When trying to import metadata, I got the following error:
“The connection has failed. [nQSError: 17014] Could not connect to Oracle database. [nQSError: 17001] Oracle Error code: 12154: message: ORA-12154: TNS:could not resolve the connect identifier specified at OCI call OCIServerAttach.”

I have the Oracle client installed on this machine. 
The tnsnames.ora file exists at <AdminTool_path>\<BI_DOMAIN>\config\fmwconfig\bienv\core directory.
I can tnsping the database.

I found that if I removed the repository variable from the data source name & user name fields and hard code the values from those variables in, the import metadata wizard is able to connect to the database successfully.