laravel nova httpexception no message

You've just added Nova to an existing production/development site and you get this error: 

Symfony \ Component \ HttpKernel \ Exception \ HttpException No message
lang-bash

The audit trail of troubleshooting started here: https://github.com/laravel/nova-issues/issues/718 

That issue refers to: https://github.com/laravel/nova-issues/issues/707 

To solve the problem, check your `.env` with local versus production versus staging and then it will most likely work.