Unless you can show how this question has ANYTHING to do with SQL Developer mark it ANSWERED and repost it in the SQL and PL/SQL forum
That 'pretty serious flaw' is in your code. DBMS_OUTPUT never displays ANYTHING. All it does is make an internal buffer available that can be used to hold data that you MAY want to display AFTER the code has finished execution.
The client tool has to FETCH the contents of the buffer and it can only do it after the code has completed. If you fill up the buffer you get that exception.
The solution is to NOT misuse DBMS_OUTPUT like that. Write your own code to produce results.
Wo wait a second mister. I did not write any code for SQL Developer in my life. So how can it be my code you are talking about? Unless you cannot read at all, I did specify that this error was from SQL Developer and Using the Report " Last AWR Report" in the title.You are doing a dis-service to your GURU ranking on the Forum.
Do try to read the original posts before your start insulting people.
The original poster is running a report from within SQL Developer. The report is provided with SQL Developer and it is SQL Developer code which is failing.
I think the question has everything to do SQL Developer.
Perhaps an apology is in order.