importaddress not working

[btc123thatthere]

Running Qt version 5.15.5.
On the console window, when I try the imortaddress command, it returns:

Requested wallet does not exist or is not loaded (code -18)

..even though the wallet is loaded.

If I close the wallet and try again, it says:

No wallet is loaded. Load a wallet using loadwallet or create a new one with createwallet. (Note: A default wallet is no longer automatically created) (code -18)

Anyone know why it's not able to use the wallet?

[nc50lc]

Running Qt version 5.15.5.

How about Bitcoin Core's version?
The latest Bitcoin Core version 26.0 uses QT v5.15.10.

Anyone know why it's not able to use the wallet?

I'm unable to reproduce this in v26.0 with "deprecatedrpc=create_bdb" to create a legacy wallet file.
The wallet loads and I'm able to import a watch-only address.

Try upgrading to the latest version and/or try manually loading the wallet via loadwallet "wallet_name" command.
See if it'll actually load without any error, if not, there may be something wrong with the wallet.dat file or the way it's loaded. (more info on that may help)

[btc123thatthere]

Running Bitcoin Knots version v25.1.knots20231115 (the latest version of Knots.)

The wallet file I tried adding it to is a brand new one.

When I try to the loadwallet command, it says "Wallet useage is restricted. (code -18)".

Using a non-Descriptor Wallet didn't make any difference.

I tried to use Sparrow wallet aswell but it looks like it won't import particular addresses.

UPDATE: When I tried using Bitcoin Core v25.?.? it came up with a Descriptor wallet error, even though it's not actually a Descriptor wallet.
 I installed the latest Bitcoin Core (v26.0.0) and now it's working (with the original wallet) but when I close it and run Bitcoin Knots it still shows the error. (To be clear: I've never run Core and Knots at the same time.)
So the problem is partially solved, though I don't know why knots20231115 and Core v25.?.? wouldn't let me add a watch-only address using importaddress.

[nc50lc]

Running Bitcoin Knots version v25.1.knots20231115 (the latest version of Knots.)

I've just finished testing Bitcoin Knots' latest version and it seems like an unreported issue,
you can report it to their repo to see if the developers can make it work.

For now, the workaround is to use the command line instead.
I used bitcoin-cli to issue the command and it worked as intended, of course set the necessary config/args to enable RPC.