You are not the only one... I am too getting the same error after update. There was an update just recently released, and I thought it would sort out the issue, however to no avail.
Getting the same error message:
(name).com 403 Forbidden Error Page
If you arrived here due to a search or clicking on a link click your Browser's back button to return to the previous page. Thank you.
Thanks for putting the question here. I would request the developer of the plugin to find the solution and please do not ask me to change the file permissions, as it's not related to that. The plugin worked earlier with 755 permissions, and it should work with same. And changing the file permissions for each and every file is a tiring job, which is not gonna help. I have noticed a lot of people going through this error, so its definitely related to your second last update.
Do a great job guys, before I give up on this plugin.. thanks.. !!!