MVC 5 @Scripts.Render("~/bundles/bootstrap") error 'Object reference not set to an instance of an object.'

Try changing "new ScriptBundle" to "new Bundle" in your "RegisterBundles" within BundleConfig:

bundles.Add(new Bundle("~/bundles/bootstrap").Include("~/Scripts/bootstrap.js"));

I have the same issue after updating bootstrap to the latest (v5.0.2) via Nuget. I see an answer above about changing ScriptBundle to Bundle with minified js. It is not a real solution for this issue. Script bundling is used to minify scripts only on release mode. We need unminified version on debug mode for debugging. So if you are already using minified js, you do not need to add it to bundleconfig.

I tried bundling with both bootstrap.js and bootstrap.bundle.js and got the same exception at script render phase.

I trimmed very long stacktrace as below:

System.NullReferenceException
  HResult=0x80004003
  Message=Object reference not set to an instance of an object.
  Source=WebGrease
  StackTrace:
   at Microsoft.Ajax.Utilities.JSParser.ParseObjectLiteralProperty(Boolean isBindingPattern)
   at Microsoft.Ajax.Utilities.JSParser.ParseObjectLiteral(Boolean isBindingPattern)
   at Microsoft.Ajax.Utilities.JSParser.ParseLeftHandSideExpression(Boolean isMinus)
   at Microsoft.Ajax.Utilities.JSParser.ParseUnaryExpression(Boolean& isLeftHandSideExpr, Boolean isMinus)
   at Microsoft.Ajax.Utilities.JSParser.ParseExpressionList(JSToken terminator)
   at Microsoft.Ajax.Utilities.JSParser.ParseMemberExpression(AstNode expression, List`1 newContexts)
   at Microsoft.Ajax.Utilities.JSParser.ParseLeftHandSideExpression(Boolean isMinus)
   at Microsoft.Ajax.Utilities.JSParser.ParseUnaryExpression(Boolean& isLeftHandSideExpr, Boolean isMinus)
   at Microsoft.Ajax.Utilities.JSParser.ParseExpressionStatement(Boolean fSourceElement)
   at Microsoft.Ajax.Utilities.JSParser.ParseStatement(Boolean fSourceElement, Boolean skipImportantComment)
   at Microsoft.Ajax.Utilities.JSParser.ParseBlock()
   at Microsoft.Ajax.Utilities.JSParser.ParseArrowFunction(AstNode parameters)
   at Microsoft.Ajax.Utilities.JSParser.ParseLeftHandSideExpression(Boolean isMinus)
   at Microsoft.Ajax.Utilities.JSParser.ParseUnaryExpression(Boolean& isLeftHandSideExpr, Boolean isMinus)

I think there is a js format issue in new bootstrap.js or bootstrap.bundle.js which causes the parser crash.

As @Manoj Salvi commented, Bootstrap 5 can be successfully bundled with:

bundles.Add(new Bundle("~/scripts/core").Include("~/content/scripts/bootstrap.bundle.min.js"));

public class BundleConfig { // Paketleme hakkında daha fazla bilgi için lütfen https://go.microsoft.com/fwlink/?LinkId=301862 adresini ziyaret edin. public static void RegisterBundles(BundleCollection bundles) { bundles.Add(new ScriptBundle("~/bundles/jquery").Include( "~/Scripts/jquery-{version}.js"));

        bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(
                    "~/Scripts/jquery.validate*"));

        // Geliştirme yapmak ve öğrenme kaynağı olarak yararlanmak için Modernizr uygulamasının geliştirme sürümünü kullanın. Ardından
        // üretim için hazır. https://modernizr.com adresinde derleme aracını kullanarak yalnızca ihtiyacınız olan testleri seçin.
        bundles.Add(new ScriptBundle("~/bundles/modernizr").Include(
                    "~/Scripts/modernizr-*"));

        bundles.Add(new ScriptBundle("~/bundles/bootstrap").Include(
                  "~/Scripts/bootstrap.js"));

        bundles.Add(new StyleBundle("~/Content/css").Include(
                  "~/Content/bootstrap.css",
                  "~/Content/site.css"));

        bundles.Add(new Bundle("~/bundles/bootstrap").Include(
                   "~/Scripts/bootstrap.js",
                   "~/Scripts/respond.js",
                   "~/Content/site.css"));
    }
}

create new mvc project go to file manager copy all Script and bootstrap files paste your running project.

Try downgrading your bootstrap version. I was on 5.1 and I downgraded to 4.6 and it works now.