Reply To: 404 page not found

The problem doesn’t seem to exist on the back end… only on the front.

By changing the custom post type’s name from ‘room’ to ‘ci_room’ worked great. Of course all queries and all template files need renaming.

I also tried on your plugin a mass find/rename of room to theroom and I also changed the fields ‘room’ and ‘roomnumber’ to ‘theroom’ and ‘theroomnumber’ in the wp_reservations table. While the admin panel throws some notices about undefined indexes such as overview_show_therooms, table_filter_theroom, table_theroom, the frontend seems to work, i.e. no 404 is thrown on form submit.

The fact that the problem happens only on form submission in the frontend, lead me to think that there is something wrong with the POSTs. Maybe you could try changing it only during the submission, so that the rest of the code won’t change.