Bug report / Question on "Error: JS: SyntaxError: Invalid range in character class."

Hi.

I check my sites on a regular basis in https://validator.w3.org, this 
tool has helped me reducing html5 errors to zero, thank you so much!

But starting this week, i got a strange error:

*Error*:JS: SyntaxError: Invalid range in character class.

https://tigretienda.com/


With no extra input on the error itself, i don't know what to do. But i 
think is some kind of new feature on the validator because before that 
the site performed well on the validator (all green). These sites has 
the same behavior:

https://cookingdepot.com/
https://tiendanecaxa.mx/
https://prada.mx/

Can you help me with that? if you need more information please let me know.

I attach a pdf with the results for the site https://tigretienda.com/

Thanks.
-- 
Luis García