accounts.last_owner
The operation would leave the workspace with no owners; it was rejected.
accounts.last_owner is returned when a role change or member removal would result in zero owners for the workspace. The platform enforces that every workspace always has at least one owner. This check is performed under a SERIALIZABLE transaction so concurrent demotions cannot both succeed.
The target member is the only remaining owner in the workspace, and the operation would demote or remove them.
Promote at least one other workspace member to owner before demoting or removing the current sole owner.
{
"error": {
"code": "accounts.last_owner",
"message": "workspace must have at least one owner",
"request_id": "req_01900000abc"
}
}