Today i ran a powershell script that lists all the features on my Sharepoint 2013 system along with their 'scope' and 'GUID'. I noticed while looking at the list that it also includes features that were long ago un-installed.
One of these listed but un-installed features was part of a solution that installed a custom masterpage. After it didn't work i un-installed it. Then in VS i changed the scope from "web" to "site", rebuilt the package and tested on a 2nd clean test system where it worked perfectly. But when i try to install the solution on my original test system, it installs but my websites become unavailable until i un-install it.
The problem "i think" is that the feature in my new solution has a scope of "site" but Sharepoint still has a record of the feature in the system and lists it's scope as "web".
Now i could change the feature GUID of my new solution but i'd rather find out how to get rid of this old feature information that Sharepoint is hanging on to.
Does anyone know how i can delete or change this info within Sharepoint?