LsClient cannot fix a broken Lansweeper installation. LsClient is a tool for scanning Windows computers. It does nothing but scan. The popup you're referring to is a popup explaining how to use LsClient, as you need to run this tool with a script.
The number one explanation for your web console being inaccessible is your web server service (IIS or IIS Express) being down. You likely restarted the service at one point. It's also possible that the upgrade was still in progress when you tried to access the console.