Angular 4, custom ErrorHandler doesn't recognize custom Error

I tried to create a custom global ErrorHandler and followed the instruction detailed here

application-error-handler (just the important parts)

export class ApplicationErrorHandler extends ErrorHandler {

    constructor(private injector: Injector) {

    handleError(error: any): void {

        if (error instanceof ApplicationError || error.originalError instanceof ApplicationError) {
        else {


 providers: [
        provide: ErrorHandler,
        useClass: ApplicationErrorHandler

app.component (only the important part)

public ngOnInit(): void { 
    const error = new ApplicationError();
    error.message = "fehler";
    throw error;


export class ApplicationError implements Error {
    name: string;
    message: string;
    httpStatus?: number = 404;
    applicationStatus?: number;
    errorMessageTranslationkey: string;
    handled: boolean = false;

in my app.component I throw an ApplicationError (in ngOnInit), my ErrorHandler gets called successfully.
But my error in handleError is always of type Error and error.originalError is always undefined no matter if I throw my custom error and there the if will never resolve to true.

I have no idea why and how this happens.
What I see is that the error gets, so I assume, wrapped because when I debug I see error: Error: [object: Object] at viewWrappedDebugError (vendor.bundle.js)

Any idea what might cause this issue and how I can resolve it?

As suspected it has something to do with Debugmode. As soon as I enable prodmode with enableProdMode(); it works as expected.

Still this doesn’t really answer my question yet.

How can I handle my custom error in angular’s debug mode?

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You encounter this problem because ApplicationError is not an Error. You can use the following code in order to create a custom error: export class ApplicationError extends Error { httpStatus?: number = 404; applicationStatus?: number; errorMessageTranslationkey: string; handled: boolean = false; constructor(message?: string) { super(message); =; Object.setPrototypeOf(this, ApplicationError.prototype); } } Related to the topic of creating a custom error, check also these links in order to have a full idea on the subject: extending Error, Array, Map in TypeScript referenced here Error – Custom Error Types section Why this needs to be an instance of Error? Because your… Read more »