Disabling mod_sec

If some requests from MapSVG to the server are failing without any obvious reason, it could be caused by the mod_sec Apache module that blocks suspicious requests.

What you could try to do first is disable mod_sec entirely and see if that helps. If it does, check the mod_sec logs and find the reason of the blockage.

How to disable mod_sec: add the following lines to the .htaccess file in your WordPress root folder:

<IfModule mod_security.c>
    SecFilterEngine Off
    SecFilterScanPOST Off