The mod Productivity Research Fork (2.1.0) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event ProductivityResearch::on_lua_shortcut (ID 43)
LuaGuiElement API call when LuaGuiElement was invalid.
stack traceback:
[C]: in function 'index'
__ProductivityResearch/control.lua:24: in function 'add_titlebar'
ProductivityResearch/control.lua:90: in function 'build_gui'
ProductivityResearch/control.lua:221: in function <ProductivityResearch/control.lua:217>
