Hi @ch3loxx
please could you clarify what you mean by “save the page”?
This plugin is intended to create widgets and not for editing pages, so it seems that “saving a page” could be related to the features provided by the plugin.
Please could you have a look at our FAQ and provide additional information.
Generally speaking, the “403 Forbidden” error is related to some protection at the web-server level rather than at the WordPress level, so there should be some web-server component that blocks the access (i.e. a web application firewall like mod_security).