So tonight, I decided to upgrade my personal sites to DNN 4.9.3. What could go wrong? Upgrading between 4.6.x versions and greater is easy since the XmlMerge functionality was introduced.
Wow! I was wrong!
I backed up both the database and the file system (which should always be done no matter what type of upgrade), downloaded the upgrade files from dotnetnuke.com, unzipped the contents over my current site files and upgraded. So far so well.
BAM! Did not even make it to the upgrade screen. Big fat yellow ASP .Net exception screen stating Request for the permission of type 'System.Web.AspNetHostingPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
Not exactly the most straight forward error message. At this point, I started going through Google, and still nothing. But then I started thinking, if it's a permission issue, I need to check what the permissions were on the file system. Since the site wasn't even rendering, I figured it might be a permission issue on the libraries within the bin directory. I checked the permissions, and sure enough, the user account I have associated with .Net Application Pool was nowhere to be found. After adding the appropriate permissions to the Bin\ directory and performed an app restart, the site worked fine!
I say it's an IIS 7 issue primarily because this is the first time I've updated a DNN site on IIS 7. On any IIS 6 sites I have never ran into this issue. If anyone has, I'd like to hear what steps were taken during the upgrade process.