Having trouble getting electrum to open cold coin skeleton wallet

[mudaggressive]

Hi All,

I'm setting up my new cold coin wallet (awesome product) and have had no problem up to the step of syncing it with off line Electrum wallet.
1) I created on cold card an Electrum wallet on the micro sd card, following instructions I think.
2) I put the sd wallet in the pc, and can see the wallet etc.
3) I install Electrum from verified install file, and open the testnet version of Electrum.
4) I attempt to open the wallet file from cold card and get an error message

"Cannot load wallet invalid extended key format " etc.....


as shown here:

https://www.screencast.com/t/oUfyOUyvaZ

 Any ideas about what I am doing wrong or how to get past this stopper?

Many thanks in advance.

MA

[NotATether]

Launch Electurm normally, not in testnet, and open the wallet file again. The cold coin wallet is using a p2wpkh mainnet master public key (i.e. version 0x04b24746), but this is not recognized on testnet.