[Error Message] MyCode staff notice fails to work

[ThatOneForest]

I have had problems with making a mybbcode using the Mycode on the ACP tool, I typed the following information into the Mycode:

• Title:Founder's Message
  
• Short Description:Founder's Message for only the founder's staff
  
• Regular Expression:
  

  \[founder\](.?)\[/founder\]

• Replacement:

  <p class="founder_bb"><img src="images/icons/information.png" alt=""/>&nbsp;$1</p>

• CSS Code:

  /* ADMIN / FOUNDER NOTICE */
  .mod_bb{
       background:#B80000 ;
       color:#000000;
       padding:.8em;
       margin-bottom:1.6em;
       border:2px solid #DC364E;
  }
  .mod_bb img{
       position:relative;
       top:2px;
  }

After all that i went and typed all the information, i get the following message: Forbidden.  I also get this error message when i attempt to submit it, is there a way round on how i can fix this issue?Thanks.