Cannot make a cache safe URL for "styles/~/SampleProject/StyleSheet.css", file not found. Please verify that the file exists under the layouts directory.

Hi All,

While trying to register a CSS file in SharePoint using CSSRegistration class as:

// Register CSS File
CssRegistration.Register("~/_layouts/SampleProject/StyleSheet.css");

We got the following error:

"Cannot make a cache safe URL for "styles/~/SampleProject/StyleSheet.css", file not found. Please verify that the file exists under the layouts directory".

One of the benefits of using SharePoint:CSSRegistration is that it prevents multiple loading of same CSS file. For Example, if we try to register a CSS file multiple times as:

// Register CSS File
 CssRegistration.Register("/_layouts/SampleProject/StyleSheet.css");
 CssRegistration.Register("/_layouts/SampleProject/StyleSheet.css");
 CssRegistration.Register("/_layouts/SampleProject/StyleSheet.css");
 CssRegistration.Register("/_layouts/SampleProject/StyleSheet.css");

The final rendered Page will have only one instance of this style sheet.

Ok. Coming back to the problem, the Resolution is to remove ~ in the URL. Hence, the correct statement would be:

// Register CSS File
 CssRegistration.Register("/_layouts/SampleProject/StyleSheet.css");

Here is a good source to know more about SharePoint:CSSRegistration:
http://tommdaly.wordpress.com/2012/05/02/sharepoint-cssregistration-or-link/

Thanks !