Integration Studio: Oracle: Error retrieving tables

Integration Studio: Oracle: Error retrieving tables

  
When performing the "Import entities from database" action using OutSystems Integration Studio, I can select my database connection I configured using OutSystems Service Center (and tested succesfully), I can also select the database I want to import entities from succesfully, but the next step fails with this error:

Error retrieving tables: ssServiceCenter.ExcptIntegrationStudio: ORA-12704: character set mismatch

According to the oracle error description (http://ora-12704.ora-code.com/), this error is caused by an invalid character set being used in the query to the Oracle database. Is there any way I can solve this?

The oracle database I am trying to connect to is a Oracle 8 database. The database's character set, retrieved using the query:
SELECT value$ FROM sys.props$ WHERE name = 'NLS_CHARACTERSET'
is: WE8ISO8859P1