[MainNet] Cannot activate node

Hello everyone,
I am totally new to Algorand, I’m trying to activate my node on the MainNet but I always receive the error:

Couldn't sign tx: key does not exist in this wallet (for multisig accounts, writ e tx to file and sign manually)

I’m using the command:
./goal account changeonlinestatus -a 'MyAddress' -o=1 -w 'MyWallet'

My node is 100% synchronized with the MainNet after a few days, and I have registered an account with a participation key.

Can anyone give me some hints?
Thank you

If your kmd instance does not have the secret key (which is what is recommended), you need to generate the transaction without signing it using the --txfile flag. Then you sign the transaction following https://developer.algorand.org/docs/features/transactions/offline_transactions/.

The page https://developer.algorand.org/docs/run-a-node/participate/online/ describes the whole process.