Not able to run locally

[KshitijMhatre]

The conflicting dependencies of eslint-plugin's prop-type version and material-ui's own is
apparently causing problem at
postCards.js @line 57 while applying styles to Button component.

while forwarding ref internally material UI is accessing PropTypes of component Button for prop color. No matter what props are passed via themes or class names the eslint is referencing 15.6.2 of prop-types which does not support PropTypes.elementType (15.7.0 introduced it).
similar issue

To get around this I tried building and serving the build directly using serve and the custom express server. But browser policies are blocking js showing X-Content-Type-Options 'nosniff'
mismatch.

workaround that worked comment the mentioned line XD