What´s wrong with dbms_output ?????

Is there anyone who can help me getting output from stored procedures?

When I check the package dbms_output using the sys-account, all works fine.
When I am connected as user, the following error occurs:

Connected to:
Oracle7 Workgroup Server Release 7.1.3.3.3 - Production Release PL/SQL Release 2.1.3.2.1 - Production

SQL> set serveroutput on;
ERROR:
ORA-04068: Der bestehende Status der Pakete wurde aufgehoben ORA-04067: Ausführung gescheitert, package body "user.DBMS_OUTPUT" existiert ni
ORA-06508: PL/SQL: aufgerufene Programm-Einheit ist nicht zu finden ORA-06512: in Zeile 1

Sorry for not translating to english.
I tried to connect as sys/<password>, then to execute the statement SQL> set serveroutput on;
and then to connect as user, but the error is the same.

Then I granted all the priviledges, sys has to the account user, (Oracle UserManager)
but the same error happend.

What is going wrong?

Thanks for any help

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