How can I use Server.MapPath() from global.asax?

Question

You could try System.Web.Hosting.HostingEnvironment.MapPath().

No HttpContext required.

Use AppDomain.CurrentDomain.BaseDirectory because Context might return null !!

When in Global.asax, use the context object:

context.Server.mappath()

Context lets you access also the session collection, the request object, the response object. Very useful when you want to log errors, for example