I just upgraded a test instance of my sitecore server to 8.2 (original release) from 8.1 (original release). I've followed all of the steps in the upgrade document, and now as I'm doing some manual testing, I've hit this error. I have a not-upgraded test environment that is working fine.
Summary method that the .NET code is looking for is a partial HTML file that exists in the correct place in my file structure (I didn't change it when I upgraded), but now it's not finding the file. I did add a non-partial version of the file (using Summary.cshtml instead of _Summary.cshtml), however, that didn't get me anything.
How do I go about figuring out how to fix this issue?