Summary
When loading Laserfiche Forms with Internet Explorer 10, you may receive an HTTP 400 error and Internet Explorer 10 displays "The webpage cannot be found."
Workaround 1
Enable Compatibility View mode for Internet Explorer 10.
Workaround 2
Explicitly configure Laserfiche Forms to not use Cookieless authentication.
<forms loginUrl="~/Account/LogOn" timeout="20160" name=".LFFORMSAUTH" cookieless="UseCookies" />