When running your macro I'm getting the error
Error: RegEx (44): The field "Challenge Name" is not contained in the record.
Possibly because the weekly challenge index has mysteriously disappeared from the page
All Solvers! We just want to make a quick note that we will not be posting Challenges on 12/24 or 12/31 due to the holiday season. We will resume challenges on December 7th! As always, if there are any challenges you'd like to propose for 2019 - feel free to contact me at firstname.lastname@example.org.