The server 'unitsys@cloud' requires encryption, but your server is not configured with the encryption key. To configure your local server make sure you become the admin of the server (owner), try again and you will be asked to enter encryption key. Otherwise, ask your sysadmin or search 'Encrypt all data' in the online docu.
I got this error, but I couldn't find the encryption key. When creating the repository, I put the encryption checkbox, but I didn't do anything else.
cm sync SeverskMuseum@<REP>@cloud p4multibranch perforce:1666 --mainbranch=//SeverskMuseum --branchesfolder=//SeverskMuseum --user=<USER> --pwd=<PWD> --tmpwkpath = c:\p4wks
p.s this repo have only main branch