I'm updating from v 2.3.6.6 MSSQL  to 2.6.0.0 MSSQL.   I had my ups and down but after a clean install most of my problems are gone.

Except that the link to the file manager returns a 404 file not found. /FileManager?view=fullpage

It works if you fix the URL to this: /Admin/FileManager.aspx?view=fullpage

I check the code and it looks like there is a bug in the onload event of the Web/Controls/FileManagerLink.cs control.
The assignment to NavigateUrl is incorrect.

    if (SiteUtils.SslIsAvailable()) {
        NavigateUrl = basePage.SiteRoot + "/FileManager" + queryString;
    }
    else {
        NavigateUrl = basePage.RelativeSiteRoot + "/FileManager" + queryString;
    }

The literal in the above code should be changed to "/Admin/FileManager.aspx" to make it work.

Yes, I have .Net 4.7 installed on a Win 2012 R2 server.
It seems like the code doesn't work in Classic pipeline mode.  I switched my app pool to Integrated and it started working.

But now it seems that the new file manager doesn't work with multiple sites (using folders). Each time I clicked on it. It brought up the file manager for the main site (ID=1) even if I am in one of my other folders.

The other problem I found with using Integrated pipeline was the default document causes a redirect loop. I don't have any rewrites.

Thanks Joe, that file fixed the File Manager for multiple sites (using folders).

The only thing left is the redirect loop. But in checking the Administration>Advanced Tools>Redirect Manager page that gave me an idea.

I added '/child' redirects to '/child/default.aspx' at the main site and that fixed my problem. It brought up my highest level page for that site.

Thanks again Joe!