I'm trying to upgrade a DNN site from 3.3.7 to 4.9.5 and I am having major problems.  Here are the steps I took and what I am now experiencing.

1. Stopped IIS
2. Changed ASP.NET version to 2.x
3. Renamed web.config to web_3x.config
4. Extracted the 4.9.5 install package over the existing directory
5. Gave "NETWORK SERVICE" modify permissions on the directory (recursively)
6. Merged settings from web_3x.config to new web.config (sql connection, machine keys, etc.)
7. Turned IIS back on
8. Browsed to site-url/Install/Install.aspx

I'm experiencing all kinds of compilation errors, and they are different every time I refresh the page.  I deleted everything in C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files but it didn't help.

Here are some examples:

• BC30560: 'DataProvider' is ambiguous in the namespace 'DotNetNuke.Modules.UserDefinedTable'.
• BC30560: 'DataProvider' is ambiguous in the namespace 'DotNetNuke.Modules.Discussions'.
• BC30560: 'ISearchable' is ambiguous in the namespace 'DotNetNuke.Entities.Modules'.
• BC30663: Attribute 'AssemblyTitleAttribute' cannot be applied multiple times.
• BC30560: 'Reflection' is ambiguous in the namespace 'DotNetNuke.Framework'.

I really don't think I should be modifying core DNN files to get this working.  Please help!

In my App_Code directory, I had several subdirectories that looked like they belonged in the root website folder:

• admin
• components
• controls
• DesktopModules
• HttpModules
• Portals
• Providers
• Solutions

I ended up moving all these directories to the root directory and overwriting the existing files.  This worked!