I am not sure if you tried to customize the app from our apps marketplace. Since the error is not self explanatory, I would suggest opening a support request. In the meanwhile, you can open If so try to install it again and make the changes gradually. Another option is to use the Activity Stream App that can be found here: http://www.clarizen.com/appsmarketplace/item/activity-stream.html
Since the use case is an Audit Trail, in one of the last HotFixes, we release a new Data Object, that object main purpose is to create audit applications. I believe that in the next few weeks our product team will release an application that is based on this object.