I'm trying to upgrade an 8.1 install to 8.2. I've followed the steps in the guide so far, including installing the UpgradeInstallationWizard package.
When I select the .update package and try to progress to the next step I get this unhelpful error message,
XML Parsing Error: no element found Location: http://<mysite>/sitecore/admin/UpdateInstallationWizard.aspx?page=1 Line Number 1, Column 1: ^
The sitecore logs aren't giving me any information on what the problem is. Where can I look to find out why the upgrade installation wizard isn't happy with the .update package I'm trying to install?