The mod Hextorio - Build in hexagons (1.9.4) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event hextorio::on_tick (ID 0)
hextorio/api/trades.lua:2098: bad argument #1 of 2 to 'pairs' (table expected, got nil)
stack traceback:
[C]: in function 'pairs'
hextorio/api/trades.lua:2098: in function 'convert_trade_id_array_to_trade_array'
hextorio/api/gui/hex_core_gui.lua:472: in function 'update_hex_core'
hextorio/api/gui/hex_core_gui.lua:1036: in function 'callback'
hextorio/api/event_system.lua:32: in function 'trigger'
hextorio/api/item_value_solver.lua:1038: in function 'phase_finalize'
hextorio/api/item_value_solver.lua:1058: in function 'process_step'
hextorio/control.lua:191: in function <hextorio/control.lua:177>

This looks like the result of some (or all) item values resolving to undefined values, likely due to significant recipe changes. Recipe changes in general should be completely fine and are handled intuitively by this mod, but I suppose it's possible that some recipes could be fundamentally reworked such that the item value solver doesn't traverse the recipe tree correctly, where the game's standard recipe system is no longer intact. What mods are you running? I added a safeguard for 1.9.5 so that the game doesn't crash when this happens, but note that you won't see any trades in some (or all) hexes.

occurs only only-time. I just wanted to let you know

my own mods ;-) und some other
base
elevated-rails
quality
recycler
space-age
0-Kux-PreEvents
AsphaltRoadsPatched
BottleneckLite
chests-in-space
color-coding
compaktcircuit-factorio21
creative-mod
EditorExtensions
even-pickier-dollies
EvenDistributionLite
expandtooltip
factoryplanner
FactorySearch
Fill4Me
FilterChests-factorio21
flib
gvv
hextorio
kry-picker-complete
kry-picker-extended
kry_stdlib
Kux-BlueprintExtensions
Kux-CoreLib
Kux-CraftingTools
Kux-CreativeItems
Kux-Factorium
Kux-GridLines
Kux-GuiLab
Kux-GuiLib
Kux-LuaConsole
Kux-Modifications
Kux-OrbitalIonCannon
Kux-PersonalTeleport
Kux-PowerPoles
Kux-ProductionRates
Kux-PrototypeExport
Kux-Radars
Kux-RawDataProvider
Kux-SlimInserters
Kux-SmartLinkedChests
Kux-SolidifiedFluids
Kux-SpeedButtons
Kux-SpeedyBotStart
Kux-VirtualSignals
Kux-ZoomRunning
logistic-request-helper
logistic-request-share
micro-machines
mini-machines
mini-micro-settings
Mining_Drones_Redux
Mini_Trains
more-signals
nonight
packing-tape
Pi-C_lib
pump
Quicksearch
RateCalculator
RPGsystem
Shortcuts-ick
sign-post
SmallRobots
Smart_Inserters
smg-equipment
textplates
WideChests
WideChestsAllTypes
WideChestsUnlimited
yafla
zzz-Kux-PrototypeExport-Compose