V3.5.7 Crash with nil inner

[RedRafe]

Description

22646.116 Error ServerMultiplayerManager.cpp:92: MultiplayerManager failed: "The mod Recipe Book (3.5.7) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event RecipeBook::on_gui_click (ID 1)
__RecipeBook__/scripts/formatter.lua:60: attempt to concatenate local 'inner' (a nil value)
stack traceback:
__RecipeBook__/scripts/formatter.lua:60: in function 'rich_text'
__RecipeBook__/scripts/formatter.lua:276: in function 'get_base_tooltip'
__RecipeBook__/scripts/formatter.lua:566: in function <__RecipeBook__/scripts/formatter.lua:534>
(...tail calls...)
__RecipeBook__/scripts/gui/search/index.lua:161: in function 'update_visual_contents'
__RecipeBook__/scripts/gui/search/actions.lua:378: in function '?'
__RecipeBook__/scripts/gui/search/index.lua:41: in function 'dispatch'
__RecipeBook__/control.lua:298: in function 'handle_gui_action'
__RecipeBook__/control.lua:305: in function 'read_gui_action'
__RecipeBook__/control.lua:315: in function <__RecipeBook__/control.lua:313>"

Reproduction

Not sure of what the actual steps to reproduce this are as it's from a MP map. I can provide the modlist or a save file for this as it may be mod-dependant

[RedRafe]

RBv3.5.7, IR3 v3.1.20 (latests) - searching for ee causes the crash

do_ir3.zip mod-list.json

[raiguard]

This is a flib bug that has been fixed for the next flib release.