I have created a simple solution (just a new content type for now) that works both on my development machine and test server. However, when I upload it the solution gallery on the live site, it just uploads and the activate popup doesn't appear and is not enabled in the ribbon (I also have to use the edit icon next to the solution to delete it, instead of the ribbon option).
What could prevent this from working, is there a setting somewhere for preventing activation of user solutions? I am a farm administrator as well as the administrator for the site collection. Everything is enable in the user permissions as well. I have tried different settings for the scope of the feature (the solution only has one defined), but it doesn't make a difference which scope is used.
The solution is a Sandboxed Solution and the Microsoft SharePoint Foundation Sandboxed Code Service is running (on the web and the application server)
When the SharePoint site collection is set to 'Records Center' it fails to activate. However, when it is a 'Document Center' it works.