Strange, i tried to do the same as shown in the video, i have a arithmetic combinator and two displays viewing an item and multiply the value with the arithmetic combinator and view the result at the second display. Then i copy this group to a position where no electric network is available and copy the settings from the original to the copied display without any crash :/.
I can definitely prevent the crash by changing the code and ignore the entity when "display" is a nil value, but i rather would like to understand why this is happening at all.
At this location in the source code "display" should be the destination display which seems to be an "invalid" entry when you do it.
The routine iterates over all known display entities and figures which one is the source and which is the destination. If by any means the list is incomplete or somehow garbled the variables source or destination may end uninitialized.
In the current case this has happened to the destination display ...
Can you please provide me the Configuration of the source display ... which item is measured, which item is displayed ....
Meanwhile i will add some debugging code which can be enabled/disabled while playing to prevent unnecessary output.
The messages will end in the console log.
