How to test the Oracle TNS connection for connecting from erwin Data Modeler?
First, you need to have a copy of the Oracle client software installed that matches the OS version of erwin. E.g. if you are using 32-bit erwin DM, you will need 32-bit Oracle client installed. If you are using 64-bit OS erwin, you will need 64-bit OS Oracle client installed.
Second, download a full trial version of RazorSQL and test the TNS connection to the database. RazorSQL, when set to use the TNS, uses the same pathway as erwin DM. This goes through the same connectivity process that erwin uses when trying to connect to that Oracle database.
In figure 1, we have tested the SYSDBA user. In the client's setup, they should instead test the same user they tried in erwin DM and remove the "SYSDBA".
If RazorSQL can connect via a TNS connection type, then erwin DM should also be able to do so.
Here is the URL where you may download a full trial version of RazorSQL to do that. The download expires 30 days after the first use: https://razorsql.com/download.html
Additional reference: I have both 32 bit and 64 bit Oracle client connectivity software on my machine but when connecting through 32-bit erwin Data Modeler to my Oracle Database I get error message: Unable to locate client connectivity software ora7nt.dll