Opentable stops supporting their web application

I've been an enthusiastic customer of Opentable ever since they were founded. But for the past few weeks when I've tried to use the web interface I get this:

I tried everything: different restaurants, different browsers, cleared browser cache (this latter a suggestion from their tech support after I waited several days for a response). I just get this same error over and over.

I wound up calling the restaurant (The Metropolitan Grill in Seattle) for a reservation ... and then I thought, hm, they do have a mobile application and I wonder ...

And it worked! I got the reservation to go through on the mobile application.

But ... why?

• Opentable is apparently using a different back end for the mobile app than for the website
• They also apparently are completely neglecting the web site back end, not responding at all to whatever's wrong with it ... for weeks?

I googled around and found this:

Priceline paid $2.6 billion for Opentable ... and now decides it's worth a lot less ... because nobody is managing it after the founders cashed out?

I don't know ... nice that the mobile app is working, but I find the web app's continuing issues enough of a downer that I'd really rather use some other service if the restaurants I am patronizing would switch to it.

Sheesh ....