Indexhibit Support

Hi.
My site: santiagoiturralde.com/

Recently I tried to load new data in my site and I found this problem:

I can't save changes when I use HTML code in edit mode. For example:

If I write this:

Then:
"Save Button" don't work and in a console I read this error:

/ndxzstudio/?a=exhibits:1 Failed to load resource: the server responded with a status of 403 (Forbidden)

jquery.js:4 POST santiagoiturralde.com/ndxzstudio/ 403 (Forbidden)
.
The server use PHP 7.2.7 and I updated the files on ndxzstudio/ as I read in this forum but it didn't solve the problem.

I don't know if I have to change something on my files or the problem is related to the server.

I really appreciate any help. Thanks!
(please, sorry if my english is not very well written!)

Finally I found the answer on my own:

I had to disable ModSecurity (into my server control panel). It was blocking the system that indexhibit use to edit the pages.
So ... If you have the same problem then turn off ModSecurity.