The mod Train construction site (0.2.19) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event trainConstructionSite::on_nth_tick(5)
trainConstructionSite/src/traincontroller-builder.lua:206: attempt to index local 'signalEntity' (a nil value)
stack traceback:
trainConstructionSite/src/traincontroller-builder.lua:206: in function 'canBuildNextTrain'
trainConstructionSite/src/traincontroller-builder.lua:135: in function 'updateController'
trainConstructionSite/src/traincontroller-builder.lua:465: in function 'onTick'
trainConstructionSite/src/traincontroller-builder.lua:478: in function <trainConstructionSite/src/traincontroller-builder.lua:477>