exports is not defined error in angular 8

I have created a JSON config that has been added to my angular 8 project. Ever since I have made changes in the way the config is imported in the project, I get error when trying to serve the project in prod mode. I am getting error exports is not defined. Not sure why it complains in prod mode and runs fine in dev mode.

Error

Following is my code changes

If you notice I have added the following two lines of code in tsconfig

"resolveJsonModule": true,
 "esModuleInterop": true

tsconfig.json

{
  "compileOnSave": true,
    "compilerOptions": {
        "outDir": "./dist/out-tsc",
        "sourceMap": true,
        "declaration": false,
        "moduleResolution": "node",
        "emitDecoratorMetadata": true,
        "experimentalDecorators": true,
        "target": "es5",
        "allowJs": true,
        "typeRoots": [
            "node_modules/@types"
        ],
        "lib": [
            "es2017",
            "dom"
        ],
        "module": "UMD",
        "resolveJsonModule": true,
        "esModuleInterop": true
    } 
}

config.json

{
    "settings": {
        "production": false,
        "userIdleMinutes": "10",
        "corePingIntervalSeconds": "10",
        "baseUrl": "http://localhost:57973",
        "loginUrl": "/Login",
        "adminUrl": "/Admin"
    }
}

This is the way it has been imported in the enviornment.ts

enviornment.ts

import config from '../assets/config.json'

// The file contents for the current environment will overwrite these during build.
// The build system defaults to the dev environment which uses `environment.ts`, but if you do
// `ng build --env=prod` then `environment.prod.ts` will be used instead.
// The list of which env maps to which file can be found in `.angular-cli.json`.

export const environment = {
    production: config.settings.production,
    baseUrl: config.settings.baseUrl,
    loginUrl:config.settings.loginUrl,
    adminUrl: config.settings.adminUrl,
    userIdleMinutes: config.settings.userIdleMinutes,
    corePingIntervalSeconds: config.settings.corePingIntervalSeconds 
};

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