Simply read this post and you issue will be solved.
issue: Load operation failed for query ‘GetAuthenticationInfo’. The remote server returned an error: NotFound.
1) This error is deceiving – the error doesn’t actually have to do with an incorrectly configured system.
2) The solution is simple
Login to your server (mine is Windows 2008 R2) > Open IIS Manager > select your Lightswitch site > click on Authentication (under IIS) > ensure ‘Anonymous Authentication’ is the only one enabled.
Restart your application from the browser and you should be good. We’ll have more to come related to Lightswitch development.
If the above solutions does not work – just REPAIR .NET 4.0 and restart your server. This just worked for me on a new server configuration.