Can’t post to group

Hello, I have a site on a sandbox server with all of the ultimate member extensions installed. For the GROUP extension, I’m not able to create a post, like, comment nor upload a photo. I’ve tried every setting within the group, such as making it public or private, auto-publish, etc. But when I mouse over the “post” button the mouse changes to a red circle with a slash over it. If I click on “like” or the photo upload image, then the page reloads with a # at the end of the url.

I searched and couldn’t find a result and it appears that there are no support docs for the groups extension.