I found the issue. Debugging remote UI process is not supported well. When you close debugger remote UI process is terminated which makes remote image unresponsive.

But it is not completely frozen. You can spawn new UI process remotely:

remotePharo evaluate: [ UIManager default spawnNewProcess ].

Or from remote playground just evaluate it directly:

UIManager default spawnNewProcess

Thanks, it works :)

I will think how to support it properly.

I wondering do you just play or you have real requirements for this scenario? (I not thought it is important)

No i am playing with it while configuring my images. It's easier to test things on both images with the uis when doing that. In the end i will embed the remote image in a raspberry pi and access it remotely, so the ui will (absolutely) not be needed. However, it is conceivable to have a desktop app that i want to connect to for example if a remote user experiences problems and i want to query things or to ask the user to perform operations.

If i do such queries i can make mistakes and i would have to proceed/abandon/close debug windows. In this case both will need a ui.