Error while running event Smart_Inserters::on_gui_opened (ID 95)
yafla/scripts/experimental/gui_builder.lua:93: Element with index 28 already has handlers
stack traceback:
[C]: in function 'error'
yafla/scripts/experimental/gui_builder.lua:93: in function 'add_actions'
yafla/scripts/experimental/gui_builder.lua:149: in function 'build'
yafla/scripts/experimental/gui_builder.lua:119: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
yafla/scripts/experimental/gui_builder.lua:154: in function 'build'
Smart_Inserters/scripts/selector_gui.lua:321: in function 'create'
Smart_Inserters/control.lua:61: in function <Smart_Inserters/control.lua:55>

Very sorry, forgot to mark it as bug

Ill check this right away, could you tell me wich scenario?

Edit: I can't replicate the problem, I need a bit more details.

I was testing game in scenario editing, to check whats new.
As probable way to reproduce:
Place inserter in scenario editor
Save n play
Open inserter GUI in game

I tried but still could not reproduce "already has handlers" is a common bug that happens in a set of cases but I still could not reproduce it.

Fine
1. Map editor
2. New scenario -> bla bla -> create
3a. Take inserters in scenario inv (not player), place it from inv
3b. Place inserters directly from build menu
4. Save n play

Nothing crashed now and all work as intended xD
Seems like some very rare scenario, as I was unable to reproduce it again, but probably quality have effect for bug appearing, would check.

Additonal steps:
1. Back to menu -> leads to scenario editor
2. Placed legendary inserters via both methods + accidentally placed inserter destroy effect
3. Play

Nothing happened too. Some rare bug, I have no idea