What to do if BTCPay Server LNURL and lightning address no longer work
Simply upgrade BTCPay Server and the LNBank plugin.
After upgrading BTCPay Server I started running into odd errors. Neither could I request payments via Zeus (connected via LNDHub to an LNBank sub-account) nor did LNURL or lightning address work.
It worked insofar as the sender could enter the lightning address and also enter an amount, but requesting the invoice failed with the following error message:
Lightning node could not generate invoice with description hash […]
I was running BTCPay Server with CLN as lightning node and LNBank to allow for sub-accounts for my family members.
How I fixed the issue
I asked the internet but did not find a solution - so it was clear to me that it was either due to my uncommon setup (CLN / LNBank) or due to me being an idiot.
As it turned out it was the latter: CLN introduced a breaking change with version 0.11 and the LNBank plugin version I was using broke due to that change. Upgrading the LNBank plugin completely resolved the issue.