Compression not working in production version

[theHimanshuShekhar]

Compression works perfectly in the development server but throws errors when using a production build.
Maybe there is an error happening when the library is being minified.
I am really new to Angular so please be kind if this is a really silly mistake on my part.

Following errors-

main.0dc9d3c7ea3836759870.bundle.js:1 ERROR TypeError: Cannot read property 'result' of undefined
at FileReader.i.onload (http://localhost:4200/main.0dc9d3c7ea3836759870.bundle.js:1:782315)
at t.invoke (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:42104)
at Object.onInvoke (http://localhost:4200/main.0dc9d3c7ea3836759870.bundle.js:1:171490)
at t.invoke (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:42044)
at e.runGuarded (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:37478)
at FileReader.removeAllListeners (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:37090)
at r.(anonymous function).XMLHttpRequest.t.responseBlob.o.function.i.(anonymous function).r.(anonymous function).(anonymous function) [as readAsArrayBuffer] (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:53036)
at http://localhost:4200/main.0dc9d3c7ea3836759870.bundle.js:1:782362
at XMLHttpRequest.n.onload [as __zone_symbol__ON_PROPERTYload] (http://localhost:4200/main.0dc9d3c7ea3836759870.bundle.js:1:781991)
at XMLHttpRequest.v (http://localhost:4200/polyfills.bf104055021a1b5ed041.bundle.js:1:51633)