Solved: Is there something wrong with const emailRegex = /[\w\.-]+@[\w\._-]+\.[a-zA-Z]{2,4}+/; that I just don’t see?

Still struggling with regex!  I’m getting the following error message when creating a JS regex variable:

ESLint found 1 issue:

const emailRegex = /[\w\.-]+@[\w\._-]+\.[a-zA-Z]{2,4}+/;

Parsing error: Invalid regular expression: /[\w\.-]+@[\w\._-]+\.[a-zA-Z]{2,4}+/: Nothing to repeat (This location is where the parser gave up trying to understand your malformed JavaScript. The actual error may be somewhere else.) 

In the error, the first  [ is highlighted in red. 

I’ve tried using  (  instead of  [ ; and adding ^ $ anchors, and escaping the \ characters without any effect,  The regex checks out OK using an online validator. I’m hoping this is just a typical rookie mistake.