I've suspended betting and am modifying the database to remove the limitation.
I'll post again once it is done. I've no idea how long it will take, sorry.
It turned out it was going to take about 8 days to fix the database table that contains the old bet archive. So rather than waiting for that to happen I made a new empty bet archive table. Betting is active again now, but you won't be able to look up details of old bets until I migrate them into the new table.
That will happen gradually over the coming weeks (and hopefully not months, but we'll see...).
None of the data is lost, it just needs a little massaging.