Receiving ORA-12541 error trying to connect through Forms/Reports
I get the ORA-12541 error message when I try to connect through
Forms6i and Reports6i Builder. I've started the listener also. I have
no problems accessing the database through SQL*Plus. I've checked
the listener and tnsnames files and everything seems okay. Any
Basically the Forms server could not find the listener. First check the tnsnames.ora file and ensure that it points to the correct server and port. If the Forms server is on another machine, test the tns resolve with tnsping from the command prompt. Finally, check the listener.
# lsnrctl status
This should show the status of the listener and the services it is listening for. Remember that when you run SQL*Plus on the database server, it does not need the listener to connect unless you specify the database tnsnames entry. Hope this helps.
This was first published in January 2006