How to fix ERROR TypeError: Class constructor HammerGestureConfig cannot be invoked without 'new'

you can go to tsconfig.json file and change your target to es5 (ECMAScript 5) like this :

  {
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "esnext",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "target": "es5",
    "typeRoots": ["node_modules/@types"],
    "lib": ["es2018", "dom"]
  }
}

credit to : https://github.com/lukasz-galka/ngx-gallery/issues/242#issuecomment-483223817

or recommended way: you can use this way if you don't want change target :

going to node_modules => ngx-gallery => bundles => ngx-gallery.umd.js

change this :

var CustomHammerConfig = /** @class */ (function (_super) {
__extends(CustomHammerConfig, _super);
function CustomHammerConfig() {
    var _this = _super !== null && _super.apply(this, arguments) || this;
    _this.overrides = ({
        'pinch': { enable: false },
        'rotate': { enable: false }
    });
    return _this;
}
return CustomHammerConfig;
}(platformBrowser.HammerGestureConfig));

to

 class CustomHammerConfig extends platformBrowser.HammerGestureConfig {
    constructor() {
        super(...arguments);
        this.overrides = ({
            'pinch': { enable: false },
            'rotate': { enable: false }
        });
    }
}

https://github.com/lukasz-galka/ngx-gallery/issues/242#issuecomment-502917803

There is a better approach to fixing this.

Modify the providers in your app.module.ts with

export class CustomHammerConfig extends HammerGestureConfig  {
   overrides = {
       pinch: { enable: false },
       rotate: { enable: false }
   };
}

and add to the Providers

providers: [
    {
        provide: HAMMER_GESTURE_CONFIG, useClass: CustomHammerConfig 
    }
]