I had a Oracle database built on a new environment, when I noticed that I had installed the 32bit database libraries instead of the 64bit.

So I installed the correct 64bit version of the Oracle database server, and I changed all the pointers to the 64bit version. I was able to start and stop the database without an issue, but when trying to access the database remotely, I got the following error:

ERROR:
ORA-06553: PLS-801: internal error [56327].

I found this solution:

shutdown immediate;
startup upgrade;
@$ORACLE_HOME/rdbms/admin/utlirp;
shutdown immediate;
startup;
@@$ORACLE_HOME/rdbms/admin/utlrp;