"fileextras.lua:58: attempt to index local 'str' (a nil value)" Error

[aoutfitter] [CO] addons/aoutfitter/lua/includes/modules/fileextras.lua:58: attempt to index local 'str' (a nil value)
stack traceback:
addons/aoutfitter/lua/includes/modules/fileextras.lua: in function 'ReadString'
addons/aoutfitter/lua/includes/modules/mdlinspect.lua:556: in function 'BodyParts'
addons/aoutfitter/lua/includes/modules/mdlinspect.lua:644: in function 'BodyPartsEx'
addons/aoutfitter/lua/outfitter/gui.lua:690: in function 'func'
addons/aoutfitter/lua/includes/modules/co.lua:218: in function <addons/aoutfitter/lua/includes/modules/co.lua:217>

1. _re - addons/aoutfitter/lua/includes/modules/co.lua:98
    2. co - addons/aoutfitter/lua/includes/modules/co.lua:222
        3. Refresh - addons/aoutfitter/lua/outfitter/gui.lua:676
            4. DoRefresh - addons/aoutfitter/lua/outfitter/gui.lua:983
                5. DoRefresh - addons/aoutfitter/lua/outfitter/gui.lua:1303
                    6. Show - addons/aoutfitter/lua/outfitter/gui.lua:1295
                        7. GUIOpen - addons/aoutfitter/lua/outfitter/gui.lua:1336
                            8. func - addons/aoutfitter/lua/outfitter/gui.lua:848
                                9. unknown - addons/aoutfitter/lua/includes/modules/co.lua:218

version
Protocol version 24
Network version 2025.03.26 (garrysmod)
Exe build: 20:13:11 Sep 17 2025 (9748) (4000)
GMod version 2025.09.17, branch: x86-64, multicore: 0
Windows 64bit

Start at addons/aoutfitter/lua/includes/modules/fileextras.lua:58 and trace the ReadString call from mdlinspect.lua:556 through BodyParts and BodyPartsEx. Reproduce the GUI refresh path shown in outfitter/gui.lua, determine why str is nil, and verify the refresh completes without this traceback.