^ for those errors guys just reload the page, I think it's caused by high traffic to the servers. Just keep refreshing until it works.
I refreshed and it now says "CoinPot is currently offline for maintenance - apologies for the inconvenience, we will be back ASAP!"

It seems to be happening on and off quite often recently but you will just have to wait it out. They always come back in the past

Edit: The have added this
More details
We are in the process of upgrading our servers and moving databases across to a faster and more reliable infrastructure. Unfortunately this means we will need to have a few periods of downtime over the next few days - this is to protect your earnings and ensure that the transfer process is a quick as possible.
Thanks you for your patience!
Seems that's what they have been doing.