The 0x6985 error happens with some transactions when using a Ledger hardware wallet through MetaMask to connect to DeFi Saver, as shown in the example screenshot below.

The error happens when MetaMask fails to properly sign and hand over a transaction to the Ledger for confirmation, which seems to be caused by MetaMask using older Ledger integration libraries.

In order to resolve this error and complete your wanted action please switch from using Ledger via MetaMask to connecting directly (natively) by selecting the Ledger option from the wallet dropdown.

Once you complete this specific action, you should be able to switch back to using Ledger via MetaMask for any other actions if wanted.