Configuring Upload Option in Group Activity Post

I am having trouble remembering where I go to configure the upload option when someone wants to post an image or other content.  I am seeing an error shown below.   My use case is posting in a group, so I don't know if this makes any difference.

Note: Currently, I am still using the soon-to-be-retired Video/Files/Music functions that I've learned will be replaced by CB Gallery, so I am not sure if the upload function within activity posts is part of this plugin.



Once I've learned how to configure this, I would like to be able to set up what can be uploaded (formats) and possibly who.  Learning where this is done would be great too!

Thanks!

Within CB Activity > Streams > Activity edit the stream you want to modify this on (note if this is Recent Activity you also need to edit Profile Activity stream) then under Integrations > CB Gallery you can configure the gallery settings. This is substantially easier in CB Gallery 3.0 (currently in Beta) as galleries have been centralized to a single management location like Streams in CB Activity.