Maybe you also already got the 404 Not Found error message
The requested URL /pls/apex/wwv_flow.accept was not found on this server.
when you submit an Oracle APEX page, …
There are a lot of reasons why this error can occur. But the above error message doesn’t tell you a lot about the root cause of the problem. The real error message can be found on your Apache Web server in the Apache\Apache\logs\error_log.xxxxx file. There you will find and entry like
[Thu Apr 3 ...] mod_plsql: /pls/htmldb/wwv_flow.accept HTTP-404 wwv_flow.accept: SIGNATURE (parameter names) MISMATCH VARIABLES IN FORM NOT IN PROCEDURE: P_T02XXX NON-DEFAULT VARIABLES IN PROCEDURE NOT IN FORM:
Without the above information, you have no chance to find out what’s causing the 404 error. But the problem is, that most developers don’t have access to the application server.
You don’t have to!
<Location /pls/apex> ... PlsqlErrorStyle DebugStyle ...
into your dads.conf/marvel.conf and after restarting the Apache server you will get the error message directly in your browser.
For more details about PlsqlErrorStyle, have a look at the documentation.
Note: Only use this setting on developments systems, because on production systems a hacker might get more information as he should!
Credit for this tip goes to Dietmar Aust!