No connection

I'm trying to get my Ardor wallet working after several years of inactivity. I've updated Java and the 2.3.4 client. I can get to the wallet and it recognises my pass phrase and shows the old balance. However, it also says "Blockchain download halted, no connection", and the Peers page shows no connected peers. If I try to add one manually, it appears for a few moments and then disappears. I have port 27874 open, according to a couple of other websites I checked with.

What do I need to do to get the blockchain downloading? I've spent some time looking for FAQs, but I've not found anything that covers this.

If it's been a long time I would suggest you start downloading the blockchain from scratch. Just shut down your node, navigate to the user directory, delete nxt_db and start the node again.

Thanks. I did that. It made no difference. I still have no connection. What would be preventing it from making a connection?

Can you check the log file for any error message? You can also PM it to me if you want.

The first warning is
2021-08-23 13:18:33 WARNING: main Your announced address does not match your external address

There's also things like:
2021-08-23 13:18:33 WARNING: Thread-2 Column in position 2 in SHUFFLING_ID_HEIGHT_IDX is 'HEIGHT' instead of 'FULL_HASH'. Fast trimming is disabled for table IGNIS.SHUFFLING

Then there's some:
2021-08-23 13:20:13 INFO: Network Listener Connection to 159.89.22.66 completed
2021-08-23 13:20:14 FINE: Network Listener Connection with 159.89.22.66 closed by peer
2021-08-23 13:20:14 INFO: Network Listener Will close connection to 159.89.22.66

2021-08-23 13:20:29 FINE: Network Listener Outbound connect failed to complete: Connection refused: no further information
2021-08-23 13:20:29 INFO: pool-2-thread-20 Connection to 157.90.161.201 failed to complete, disconnecting

I'd PM the whole thing, but I can't see how to send a private message with this forum.

Ah, I think I've found it. There was an old nxt.properties. I've renamed it and now there are some connections.

If your announced address does not match your external address, this may be the reason your node can't connect to peers (they may even be blacklisting you, need to check the code). Remove any nxt.myAddress property from your nxt.properties file, or make sure it is correct.