Please try the Script Mapping available in ASP.NET 4.5 or later to avoid a use of WebResource.axd and ScriptResource.axd. For details please see the following Microsoft blog:
ASP.NET 4.5 ScriptManager Improvements in WebForms
The Script Mapping is made available by default in the ASP.NET Web Forms project created by the template of Visual Studio 2015 or later. The master page includes the ScriptManager control in which the ScriptReferences are registered as shown below: