Many thanks for the insight, I resolved a the very similar problem

I was getting this message on  5.6.5 CE edition:

Line 460: editHyperlink.Visible = False Line 461: Else Line 462: editHyperlink.Visible = PackageController.CanDeletePackage(package, ModuleContext.PortalSettings) Line 463: End If Line 464: Else

Source File: F:\Websites\arabaviation\DesktopModules\Admin\Extensions\Extensions.ascx.vb    Line: 462

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.] DotNetNuke.Services.Installer.Packages.PackageController.CanDeletePackage(PackageInfo package, PortalSettings portalSettings) +353

It was the result of installing a zip file with many skins as zip  files ( in my case the DDRMenu theme samples).

Instead of UNZIPPING I installed it and the system took IT!

Always check any package before installing, to make sure if ti contains a single module/skin or one install package.

As some developers do not mention to state UNZIP ME" if required :)))))))