Steps to reproduce on regtest:

```
converttopsbt 02000000000101ab73dba46508bacdb49a988ddd74bc9d39c9cb7e057af060ca8c6b6861e28e3c0300000000feffffff02b828d0b20000000017a914d1954862afd728fbb055149002958e1d1b9e1f0b8700ca9a3b0000000017a91442170ccb3441cff1723af9afab6f2553103e1d578702473044022077380c6e16496d9905aef120694c329be51522847cb5d53fa74b94698c95678d02202d32c46e0e17420a83dee830fefda7d40529182f5d82be47c2b49a7b83214ab50121026d483d6628dcc3ef6e3ab9ed4937c452c263c7e0ac80eb4be97426d5da8f640500000000
```
or 
```
converttopsbt 02000000000101ab73dba46508bacdb49a988ddd74bc9d39c9cb7e057af060ca8c6b6861e28e3c0300000000feffffff02b828d0b20000000017a914d1954862afd728fbb055149002958e1d1b9e1f0b8700ca9a3b0000000017a91442170ccb3441cff1723af9afab6f2553103e1d578702473044022077380c6e16496d9905aef120694c329be51522847cb5d53fa74b94698c95678d02202d32c46e0e17420a83dee830fefda7d40529182f5d82be47c2b49a7b83214ab50121026d483d6628dcc3ef6e3ab9ed4937c452c263c7e0ac80eb4be97426d5da8f640500000000 false
```

Further reading: #13738
RPCResult{
            "{\n"
            "  \"name\" :    <wallet_name>,        (string) The wallet name if loaded successfully.\n"
            "  \"warning\" : <warning>,            (string) Warning message if wallet was not loaded cleanly.\n"
            "}\n"
                },
                RPCExamples{
                    HelpExampleCli("loadwallet", "\"test.dat\"")
            + HelpExampleRpc("loadwallet", "\"test.dat\"")
                },
            }.ToString());
    WalletLocation location(request.params[0].get_str());
    if (!location.Exists()) {
        throw JSONRPCError(RPC_WALLET_NOT_FOUND, "Wallet " + location.GetName() + " not found.");
    } else if (fs::is_directory(location.GetPath())) {
        
        fs::path wallet_dat_file = location.GetPath() / "wallet.dat";
        if (fs::symlink_status(wallet_dat_file).type() == fs::file_not_found) {
            throw JSONRPCError(RPC_WALLET_NOT_FOUND, "Directory " + location.GetName() + " does not contain a wallet.dat file.");
        }
    }
    std::string error, warning;
    std::shared_ptr<CWallet> const wallet = LoadWallet(*g_rpc_interfaces->chain, location, error, warning);
    if (!wallet) throw JSONRPCError(RPC_WALLET_ERROR, error);
    UniValue obj(UniValue::VOBJ);
    obj.pushKV("name", wallet->GetName());
    obj.pushKV("warning", warning);
    return obj;
}
static UniValue createwallet(const JSONRPCRequest& request)