Error on opening mail/collecting items

I had opened my mailbox and noticed that in addition to the Explorer's returns, there was a mail with my converted returns from the last event (coins), and a gift which I could see included 10 building permits (yay!) and something else that I now can't recall. So, happily, I ticked to collect everything.

Immediately, I got an error message:
https://ibb.co/BN9bmXQ

It wouldn't let me copy the error message, nor could I scroll through it. So because the screen had frozen (the ever-present, ever-annoying Zone Refresh, I guess), I refreshed the screen.

No extra building permits appeared, so I logged off and on again.

There are still no extra building permits, and as far as I can see, I also don't have any of the other items that I collected from the mails.

Update: I found the building licences in the star menu. It said to add them to the Mayor's House, which I've done. But it only gave me 1 extra building licence, even though it said there would be 10.

Please contact our Support Team, so they will be able to investigate this.