Please verify that a supported version of the Progress OpenEdge driver is in use. A list of supported Progress OpenEdge driver (versions: 10.2b patch 4, 11.0, 11.1). Support for version 11.2 and higher are being worked on for future releases. I do not know a precise timeline on the release for 11.2 and higher support.
Hope this helps!
We are using the Progress OpenEdge 10.2A driver
Sorry for the delay in my reply. The Tableau Desktop Technical Specifications state that it can connect to Progress OpenEdge 10.2b patch 4 and higher. I believe that was the version released after 10.1a. There might be a possibility of connecting via the ODBC connection if Progress OpenEdge has an ODBC driver.
If available for the database Tableau has an ODBC connector can be used to most data sources that have an ODBC driver. I am including several resources for the ODBC connection below. There can sometimes be limitations when using the ODBC connection versus a named connection that is listed in the explicitly on the data source page.