I’ve just really began to try and experiment with using Drupal, modules, and really starting to customize how things work. I have really been playing with open source Content Management Systems off and on over the years because I don’t feel that depending on proprietary CMS is the right approach and definitely rolling your own is not only difficult, but extremely unnecessary. Trevor Twining wrote an excellent blog article regarding using an open source vs proprietary CMS.
While following the steps outlined in the Read Me file for the TinyMCE plugin, I wasn’t able to use it at first because of an error and eventually found the solution here. Basically, the solution is find the following line in modules/tinymce/tinymce.admin.inc:
'#default_value' => isset($edit->rids) ? array_keys((array) $edit->rids) : NULL, and replace it with
'#default_value' => isset($edit->rids) ? array_keys((array) $edit->rids) : array(),