As a search user, I want to be able to know when I am not entering a proper regular expression so that I can correct my input

when I search insource:// i get An error has occurred while searching: We could not complete your search due to a temporary problem. Please try again later.

I should instead see something like insource expects a regular expression.

AC:

• User should get an appropriate error message when they don't provide a regular expression to insource