Does anyone know: when the ContractRunner config.json is loaded on the ContractNode, is it also uploaded to the blockchain? Can sensitive data be inside the config.json or would everyone see it?
No, config.json is a workstation specific file that is never uploaded to the blockchain, you can also encrypt the contract runner configuration https://ardordocs.jelurida.com/Node_Processes_Configuration.
The https://ardordocs.jelurida.com/Lightweight_Contracts#Upload_Parameters_Configuration_File API name is a bit misleading as it is used to upload the contract runner config from the client to a remote node but again this configuration is never registered on the blockchain.
This guide explains how to use the Processes feature to save and store configurations of the node that are normally lost upon restart.
Lightweight Contracts represent a framework for developing a layer of automation on top of the existing Ardor APIs.
@riker I have a ContractRunner node running Contract "X" , Logged in and running with Account X (config.json was loaded and running). Then I logged in to the same not with Account Y and tried to load a different config.json for a different contract. Everything was separate except that it was running on the same node. But I was not able to load the second config.json, nothing happened all the time. Until I restarted the node, I could load the second config.json.Is this something that you have experience before?
A node can only run contracts from a single account. In other words it can only have one contract runner.
EDIT: deleted due to misinformation provided by me