DataSelf DataSelf ETL+ DataSelf ETL+ User Guide ETL+ Troubleshooting ETL+ Troubleshooting In this section ETL+ Installation Troubleshooting Extraction Errors Upsert Missing or Duplicating Rows ETL+ Error Messages — Text of error messages reported in ETL+ log files or on ETL+ screens. T-SQL String Constants (String Literals) — ETL+ target tables (tables and columns shown in the ETL Objects panel) only support string constants with single quotation marks, (not double quotation marks). ×