The quickest way to get this done is to downgrade to 6.1.26, do the memory dump, get the keys and just enter them directly into the scope. Then re-upgrade to 6.1.35R2. All the files are available on the Siglentna website.
What does DSO firmware have to do with the SDG2042X ?
Maybe you didn't read the topic title ?
Alas, I think the firmware I'm using is too new to allow the hack, and Siglent seems to no longer offer the version that does.
First step is to get a reliable LAN connection. Period.
Best done with a connection to and via your LAN and not via a peer to peer connection although this can be done but it is more involved.
You first need know your LAN Gateway IP and Subnet address to enter into the instruments LAN configuration fields then also assign an IP to the instrument within the range of allowable IP addresses for your LAN.
Then save it to the instrument from within the instruments menu.
All this ^ can be made somewhat simpler if you have limited LAN skills by enabling the instruments DHCP where the instrument request the LAN info from your router and even assign a free IP address.
Once IP is assigned and known, DHCP can be disabled and the LAN info saved.
Now armed with the instruments IP this can be enter into your LAN connected PC for reliable connections to the instrument.
On the Siglent website there is even advice on Tenet:
https://siglentna.com/application-note/verification-lan-connection-using-telnet/