You have non-existant categories selected for your series.  Edit those series to remove the non-existent categories.

Re-upload the index.php file.  I think you've loaded a blank one into the main directory from one of the sub-directories. 

The category block is separate from the category page as it has always been.  The category page is controlled from the categories.tpl as it has a...

Well first Marauders is NOT a 3.0 skin and the author has stated that it isn't going to be updated to 3.0.  So that one isn't going to ...

About 4-5 threads down from this one is the answer to this problem.  The one labeled "MOVED: Blocks Not Showing".

I would suggest you set them back to type S.

Once your problem is solved, please go back and mark your thread as solved.  This is especially important if you solved it yourself. 

I'm not getting any tinyMCE errors so you'll have to be more specific.  You should also start a separate thread.

Most likely, the author's folders in your stories/ folder didn't get renamed from their username to their user id.  You'll need to...

As stated in the README.txt file, 1.1 skins don't work with 3.0.  You need to choose a 3.0 skin.

Please also note that 2.0 skins DO NOT work for 3.0.  As far as I know Shinigami blue is a 2.0 skin and hasn't been updated to 3.0 by the au...

Go back and read the instructions for posting a help request.

If you WANT a custom configuration you can add one.  If the box wasn't there you couldn't.

Did you turn submissions off?

That error probably means you've got a story without a category.