Fixes template resolution

main.go

@@ -134,6 +134,10 @@ func errorHandler(errorFilesPath string) func(http.ResponseWriter, *http.Request
 		for _, ext := range exts {
 			var filePath string
 
+			if !strings.HasPrefix(ext, ".") {
+				ext = fmt.Sprintf(".%v", ext)
+			}
+
 			filePath = fmt.Sprintf("%v/%v%v", errorFilesPath, code, ext)
 			if _, err = os.Stat(filePath); err == nil {
 				file = filePath