Any time someone selects a blueprint book that isn't synced to the server yet, the whole server crashes with the following error:

Error while running event cargo-ships::on_player_cursor_stack_changed (ID 36)
BlueprintRecord cannot be read while it is a preview.
stack traceback:
[C]: in function 'index'
__cargo-ships/logic/pump_placement.lua:96: in function 'is_holding_pump'
cargo-ships/logic/pump_placement.lua:144: in function 'PumpVisualisation'
cargo-ships/control.lua:340: in function <cargo-ships/control.lua:338>"

Any time someone selects a blueprint or book that isn't synced to the server yet, the whole server crashes with the following error:

Error while running event cargo-ships::on_player_cursor_stack_changed (ID 36)
BlueprintRecord cannot be read while it is a preview.
stack traceback:
[C]: in function 'index'
__cargo-ships/logic/pump_placement.lua:96: in function 'is_holding_pump'
cargo-ships/logic/pump_placement.lua:144: in function 'PumpVisualisation'
cargo-ships/control.lua:340: in function <cargo-ships/control.lua:338>"

I clicked edit and apparently it did that. Janky discussion board.

This should be fixed in 2.0.22. Thank you for the report!

This is fixed for real now in 2.0.23. This time I actually replicated the crash and proved that it is fixed.

Thanks so much! No more crashing so we can finally use this on our server! :D

An update: The latest experimental has some changes and a new function that might be relevant to this and the whole way your pump visualizer operates. This thread has all the info: https://forums.factorio.com/130790