I've sent an email to the pilgrim office about the problem. Sure others will have done the same.
Not the best time for it. Over 3,000 Compostelas yesterday and the same the day before. And now the pilgrim office want people to register via the website before visiting. Getting a big red security warning from your browser is probably not what a couple of thousand arriving pilgrims want to see...
Yes, same here. Safari informs that a certificate of the website expired on Sunday, 5 May 2024 at 01:59:59 Central European Summer Time.
There will probably be upwards of 2,000 people arriving today and wanting to register on the website. You can disregard the browser security warnings and enter the site. Though not everyone will know that or be happy to do so. Haven't tried the registration form myself. Perhaps today will be old-school with paper forms and queues up the street back to the Obradoiro. The good old days...Let's see how long it will take them to fix it ... it's Sunday today ...
For a reasonable length of time perhaps. There was a short period before Covid when waiting times to receive a Compostela could easily be three or four hours on the busiest of days. The pilgrim office introduced a queue system rather like the tickets at a supermarket deli counter. Take a numbered ticket, go away and return when your number was nearly at the top of the queue. A counter on the website gave the current number being processed. That at least meant people were not obliged to spend three hours in the street. Some might argue that the impersonal nature of the present system is a fair price to pay for speed and convenience. As I no longer ask for a Compostela it does not affect me personally.
When I checked a few minutes ago, the counter was on 876 Compostelas and now it is on 895 Compostelas. So some pilgrims will get their Compostelas today - some might not which was (albeit rarely) the case years ago on the good old peak days ...Perhaps today will be old-school with paper forms and queues up the street back to the Obradoiro. The good old days...
icon in your browser tab. i.e. the one that you see just before the text oficinadelperegrino.com. Or caminodesantiago.me for that matter. 
After the last few days I'm sure a quieter day will be very welcome!They have issued 537 Compostelas so far. It may not turn into a record day today.
Here is the full set from the TV network. The one on the way to Monte do Gozo is the San Marcos one. Scroll down for it.
They haven't paid yet. Its very common. In Spain and in the states. Not everyone keeps up with due dates for their security certificate.
