Today, an unexpected error was encountered.
I activated Hustle Pro, then cached page returned 403.
There is a possibility that the server environment may be the cause, so it can not be said to be a bug unconditionally.
But will you investigate the possibility of conflict between these two plugins?
I checked .htaccess etc, but I do not know the cause.
We will give you access to the site to provide server information, but please do not test on the site. Because 403 comes out ...
As SnapShot Pro is installed, restore it in your environment and check it.