Submitting more than one html tag cause 404 Error

Question

I'm using grocery crud with codeigniter to change some database columns,but I have a problem when I use html tags, I get 404 Not found error in firebug.

The following work:

But the following doesn't work because I have tried to style it :

When I click on source in the top left of the WYSIWYG editor and try to type in my html, sometimes it works and sometimes not:

<p>This works</p>

The following doesn't work (404 Not found):

<p> This <p>Hello</p> Not work </p>

The following doesn't work (404 Not found ):
<p></p>

The following works
<p>aaaa</p>

Any idea why do I get 404 if the I put an empty

tag but it works if I put something inside ?? Thanks in advance As long as I can see, it only works with 1 tag but if I use more than one tag it doesn't work :

<h1> This single line work </h1>

But if I use more than 1 html tag it won't work, for example the following doesn't work ( 404 Not found ?)

<h1>Hello</h1>
<h1>World</h1>

Answer 1

Though there is very little information given, have you inserted the html tags inside the visual mode of the editor or html mode ? try inserting in html mode and paste. I think the issue at your end is related to special characters.