Would like to understand how the update configuration utility connects to the Oracle database. When running the utility you could see an error like:
ORA-12514: TNS:listener does not currently know of service requested in connect descriptor.
The 15.x (including MP3) builds a connection to connect to the DB using a connection using the 4 Oracle files in the folder:
Those 4 files are used to create the connection string "//<oracleHost>:<oraclePort>/<oracleServiceName>" using oracleUsername and the decrypted database password for credentials.
Unexpected chars from VI into those Oracle installation files will cause this string concatenation to be corrupted and fail the connection.
As may be noted the above connection string syntax is using the ezconnection names resolution, but in addition to a bad string, the connection can fail if ezconnection name path is disabled.
Please make sure that on the Enforce server the following command is successful (after it prompts for the password for the user) to make sure ezconnect is not disabled.