this problem occurs on Oracle 12c database when I test procedure in SQL developer, or running via ORDS on weblogic, but it is still running via IAS web server without any error. I found similar problem:
For Oracle Application Server 10.1.2.x.x, apply the 10.1.2.3.0 Patchset (Patch 5983622) which includes PL/SQL Toolkit version 10.1.2.0.4.
For Oracle Application Server 10.1.3.x.x, this version already includes PL/SQL Toolkit version 10.1.2.0.4.
Curent version of owa_util is 10.1.2.1.9
is there a patch to solve this problem?
ORA-06502: PL/SQL: numeric or value error: character to number conversion error
ORA-06512: at "SYS.HTP", line 1105
ORA-06512: at "SYS.HTP", line 1126
ORA-06512: at "SYS.HTP", line 1144
ORA-06512: at "SYS.OWA_UTIL", line 345
ORA-06512: at line 12
probably caused by this owa_util.showpage;
You're initializing OWA env in your procedure?