To obtain some more diagnostic information, can you modify the PL/SQL Developer shortcut and add the DebugSQL parameter? For example:
"C:\Program Files\PLSQL Developer 16\plsqldev.exe" DebugSQL
Reproduce the problem and send me the debug.txt file that is generated in the %APPDATA%\PLSQL...
The %APPDATA% directory will take precedence over the installation directory, so that your customization will be preserved for existing users. This will not help for new users of course. I have added the %ProgramData% suggestion to the list of enhancement requests.
The SQL Window currently does not resolve the rowid to a table name. I have added this to the list of enhancement requests. In this case there would indeed no longer be a table order requirement for the FROM clause for updateable result sets.
Typically only one table of a query will bey key-preserved (unless there is a one-to-one relation between the tables), so only one table can be updated. The SQL Window assumes that the first table is the key-preserved table.
The Params.ini file from the installation directory is copied to the %APPDATA%\PLSQL Developer 16 directory when a user starts PL/SQL Developer. It can be maintained at this location as well, so that a software install/uninstall/update does not affect it.
You can set any command-line parameter in the Params.ini file in the PL/SQL Developer installation directory. This ensures that the parameter is used, regardless how PL/SQL Developer is started.
We have tested this with the same Oracle Client Version 23.3.0.23.9, and it seems to work fine.
Can you send the plyxon.error.txt file from the $HOME/Documents/Plyxon/Log folder to support@allroundautomations.com?
The explain plain function will update the plan_table, so it is indeed not allowed in read-only mode. We'll see if we can allow this in the next release.