Bitcoin Core 32.0's graphical wallet may disrupt co-signing with older Core wallets. A user reported on Oct. 14 that the new GUI creates PSBT v2 transaction files, which older versions cannot import, leading to compatibility issues. The fix for this has been moved to the 32.1 milestone, with a proposed GUI fix still open. Users can use the `psbt_version=0` option with RPC commands like `walletcreatefundedpsbt` or `createpsbt` to generate v0 files.