Problems with HTML Button, Show Rich Text Toggle

I'm trying to figure out some bugs for a friend who's working on a Drupal installation for his church. Unfortunately, neither of us has access to the backbone of the server, just the login and settings for Drupal. I'll provide as much information as I can here.

Drupal Version: 5.1
TinyMCE Drupal Module Version: TinyMCE - 5.x-1.x-dev

1. Clicking on the "HTML" button in the TinyMCE editor causes a popup to open and a Page Not Found error to display on the window (image here).

2. In the TinyMCE profile, when "Show disable/enable rich text editor toggle: " is set to true, nothing shows on any page that the TinyMCE editor is supposed to appear on except for the link "disable rich text", which doesn't take me anywhere when I click on it. (image here)

Any help would be greatly appreciated.