Problem in GroupDocs� Document Viewer for .NET MVC4

I have created the GroupDocs’ Document Viewer for .NET MVC4 according to the instructions given the url below.
http://groupdocs.com/blog/how-to-use-groupdocs-viewer-for-net-mvc4

But when the page is loading only the iframe is loading. It doesn’t display the document. just the loading icon.

Even though I have given the license. It seems its’ not detected.

A link to my project files is given below.
Dropbox - Error - Simplify your life

Can you please help me.

Hello,
We are sorry to hear that you have such issue. We downloaded and reviewed your project. All is fine, except this line

.FilePath(http://localhost:52199/Content/guid.txt) in the “Index.cshtml” file. method “FilePath” doesn’t support specifying an URL, only file name. So you need to change it to the
.FilePath(“guid.txt”)
and all will be fine (because file “guid.txt” is present in the “Content” folder): http://prntscr.com/42jj3l
Also we found that you are using GroupDocs.Viewer version 1.6.0.0. This is quite old version, at this moment the latest is 2.1.2, you can find it here: GroupDocs.Viewer for .NET
If you will have more questions please feel free to contact us.