DBMS_OUTPUT DOES NOT WORKS

are you talking about printing to the console?

set serveroutput on;

begin

dbms_output.put_line('Hello');

end;

/

you have two options,

SET SERVEROUTPUT ON in the worksheet

or View > DBMS OUTPUT

https://www.thatjeffsmith.com/archive/2012/03/dbms_output-in-sql-developer/

Or use View > Dbms Output to create a distinct DBMS Output tab for any connection for which you want to segregate the output...

Strange.  Does it work if you add the following line to your sqldeveloper.conf file?

AddVMOption  -Duser.language=en

If I use "AddVMOption  -Duser.language=fr" with 17.3.0 and repeat my test, I see...

Following the advise from thatJeffSmith-Oracle and Gary Graham-Oracle, using SQL Developer 17.3.0.271..2323, ...and running the worksheet commands by hitting F5 (defualt windows key for "Run Script"), we see that the "DBMS Output" window AND the Script Output window does actually show the output from DBMS_OUTPUT.PUT_LINE(...):

set serveroutput on
begin
   dbms_output.put_line('dbms_output.put_line(''soem text...'');');
end;

[Edit: English is my first language, but I do not seem to be able to spell "some"...]

And even Run Statement (Ctrl+Enter) will produce output in the Dbms Output tab.

I done it, but it does not work.

You 'done' what?

SHOW US:

1. WHAT you do

2. HOW you do it

3. WHAT results you get

See the DBMS_OUTPUT tab at the bottom of the image in Gaz reply #7?

Did you click on the + button and select the connection you want to use?

No, not a bug in the french version, but weird that it's not working

If you open the dbms output panel and enable polling for that database, does it work?