ECAT Live configuration error - Could not store into lockbox

[huanzhou1]

After upgraded to 4.2.0.2, when i tried to save live configuration, got error:

{
"Port": 0,
"ResponseStatus": {
"ErrorCode": "Could not store into lockbox",
"Message": "Could not store into lockbox",
"Errors": []
}
}

Any advise? 

[huanzhou1]

fixed after remove the old lockbox files, any reason why after upgrade not able to access? need to reset like LC lockbox?