Chatter widget error

Hello, I’ve been trying to configure the chatter widget that I’ve found on the app store: Unfortunately I get some errors that I have no clue how to solve. Attached is a screenshot with the error(s) I get. Can someone help me find out why i get all these errors? thank you all! Ada
1 answers

These all seem like straight forward errors. Most of your pages are referring to a master layout that doesn’t exist any longer.