Following Mitchel Sellers' recommendations in Upgrading to 4.9.x from 4.x, I've copied the 4.4.1 install package over my 4.5.3 test site, having carefully saved a copy of my working web.config.  I renamed release.config to web.config and collated the two with WinMerge to make sure that all my changes were migrated. When I tried to run the upgrade I got this error:

Configuration Error

Line 57:     <httpModules>
Line 58:       <!-- add name="Authentication" type="DotNetNuke.HttpModules.AuthenticationModule, DotNetNuke.HttpModules.Authentication" / -->
Line 59:       <add name="Compression" type="DotNetNuke.HttpModules.Compression.HttpModule, DotNetNuke.HttpModules.Compression"/>
Line 60:       <add name="UrlRewrite" type="DotNetNuke.HttpModules.UrlRewriteModule, DotNetNuke.HttpModules.UrlRewrite"/>
Line 61:       <add name="Exception" type="DotNetNuke.HttpModules.ExceptionModule, DotNetNuke.HttpModules.Exception"/>

I remember seeing this line when I collated, because it was in the new file and not in my old one.  I left it in because I assumed it was a new feature.  Now I'm getting an error.  Should I just delete the line?  Won't I be disabling something that's supposed to be there? 

Before I got this error, and after I got deleted the line, I just get a blank page when I try to run the installer by navingating to http://localhost/osc/Install/Install.aspx, per instructions. 

Any advice greatly appreciated.

please make sure to unzip all files from upgrade package hiearchically, overwriting existing files. This should include compression dll.