Facebook has a had a huge week with them going public with their $5 Billion IPO. However, it looks like they are facing problems with their infrastructure with the "Facebook Activity Feed" for websites showing an "invalid action type" error all across the web.
Website owners who have been using the "Activity Feed" social plugin from Facebook might notice that the feed is no longer showing up and instead an error box with the message "Invalid action type" has taken it’s place. This problem is occurring on all websites and seems to be a big problem on Facebook’s side.
The error is also apparent on Facebook’s Social Plugin code generator for all websites as seen in the screenshot above. Facebook has faced several problems in the past where the site has gone down for hours due to database problems and DNS issues among other things. However, this look like the first time that their social plugins have had issues.
If you are a webmaster who uses the Facebook Activity Feed on your website, you might see the above error. However, having the widget in question on your site does not affect loading time. We have contacted Facebook to check why this problem is occurring and will update the post when we get a response.