Hi - Just found this mod and installed the latest version 6.0.4 - never used before in my install.
Loaded a save and got a crash during load :
Error while applying migration: Extended Vanilla: Personal Equipment: Better-Power-Armor-Grid_4.0.0.lua

...rmor-Grid__/migrations/Better-Power-Armor-Grid_4.0.0.lua:7: attempt to index field '77-power-armor-mk2' (a nil value)
stack traceback:
...rmor-Grid__/migrations/Better-Power-Armor-Grid_4.0.0.lua:7: in main chunk
I've tried disabling the mod, removing my armor on to the floor, re-enabling the mod and re-loading and same error persists.
I'll try also by trashing the armor and the contents of the grid to see if that changes and report back.
Happy to try anything else specific.
Cheers!

Tried with an empty grid and dropped armor and armor in inventory empty and with grid and various other variations - error persists - assume it might be due to the fact I've never had the MoD before and there's nothing to migrate? I have no clue how mods work so wildlyh guessing of course, ill paste my full mod list below:

{
"mods":
[

{
  "name": "base",
  "enabled": true
},

{
  "name": "AdditionalPasteSettings",
  "enabled": true
},

{
  "name": "alien-biomes",
  "enabled": true
},

{
  "name": "alien-biomes-hr-terrain",
  "enabled": true
},

{
  "name": "artillery-bombardment-remote-reloaded",
  "enabled": true
},

{
  "name": "AutoDeconstruct",
  "enabled": true
},

{
  "name": "automatic-underground-pipe-connectors",
  "enabled": true
},

{
  "name": "AutomaticLogisticChest",
  "enabled": true
},

{
  "name": "auto_manual_mode",
  "enabled": true
},

{
  "name": "belt-visualizer",
  "enabled": true
},

{
  "name": "Better-Power-Armor-Grid",
  "enabled": true
},

{
  "name": "BetterAlertArrows",
  "enabled": true
},

{
  "name": "blueprint-sandboxes",
  "enabled": true
},

{
  "name": "blueprint_flip_and_turn",
  "enabled": true
},

{
  "name": "bobinserters",
  "enabled": true
},

{
  "name": "BottleneckLite",
  "enabled": true
},

{
  "name": "bullet-trails",
  "enabled": true
},

{
  "name": "chest-auto-sort",
  "enabled": true
},

{
  "name": "CleanFloor",
  "enabled": true
},

{
  "name": "even-distribution",
  "enabled": true
},

{
  "name": "extended-descriptions",
  "enabled": true
},

{
  "name": "FactorySearch",
  "enabled": true
},

{
  "name": "Fill4Me-fixed",
  "enabled": true
},

{
  "name": "flib",
  "enabled": true
},

{
  "name": "Flow Control",
  "enabled": true
},

{
  "name": "fluid-connection-indicators",
  "enabled": true
},

{
  "name": "FluidMustFlow",
  "enabled": true
},

{
  "name": "ghost-counter",
  "enabled": true
},

{
  "name": "GhostInHand",
  "enabled": true
},

{
  "name": "GhostWarnings",
  "enabled": true
},

{
  "name": "helmod",
  "enabled": true
},

{
  "name": "informatron",
  "enabled": true
},

{
  "name": "inserter-throughput",
  "enabled": true
},

{
  "name": "InserterFuelLeech",
  "enabled": true
},

{
  "name": "inventory-repair",
  "enabled": true
},

{
  "name": "LightedPolesPlus",
  "enabled": true
},

{
  "name": "LogisticTrainNetwork",
  "enabled": true
},

{
  "name": "ltn-cleanup",
  "enabled": true
},

{
  "name": "LtnManager",
  "enabled": true
},

{
  "name": "LTN_Combinator_Modernized",
  "enabled": true
},

{
  "name": "Milestones",
  "enabled": true
},

{
  "name": "mining-patch-planner",
  "enabled": true
},

{
  "name": "ModuleInserter",
  "enabled": true
},

{
  "name": "ModuleInserterSimplified",
  "enabled": true
},

{
  "name": "Nanobots",
  "enabled": true
},

{
  "name": "nco-LongStorageTanks",
  "enabled": true
},

{
  "name": "nicefill",
  "enabled": true
},

{
  "name": "nixie-tubes",
  "enabled": true
},

{
  "name": "osm-lib",
  "enabled": true
},

{
  "name": "osm-lib-postprocess",
  "enabled": true
},

{
  "name": "P-U-M-P-S",
  "enabled": true
},

{
  "name": "PickerAtheneum",
  "enabled": true
},

{
  "name": "PickerDollies",
  "enabled": true
},

{
  "name": "PickerExtended",
  "enabled": true
},

{
  "name": "PipeVisualizer",
  "enabled": true
},

{
  "name": "qol_by_morality",
  "enabled": true
},

{
  "name": "qol_research",
  "enabled": true
},

{
  "name": "QueueToFrontNG",
  "enabled": true
},

{
  "name": "quick-chest-limit",
  "enabled": true
},

{
  "name": "RateCalculator",
  "enabled": true
},

{
  "name": "RecipeBook",
  "enabled": true
},

{
  "name": "robot_attrition",
  "enabled": true
},

{
  "name": "RPGsystem",
  "enabled": true
},

{
  "name": "Shortcuts-ick",
  "enabled": true
},

{
  "name": "show-max-underground-distance",
  "enabled": true
},

{
  "name": "simhelper",
  "enabled": true
},

{
  "name": "spidertron-control-center",
  "enabled": true
},

{
  "name": "spidertron-extended",
  "enabled": true
},

{
  "name": "Squeak Through",
  "enabled": true
},

{
  "name": "StatsGui",
  "enabled": true
},

{
  "name": "StatsGui-HandcraftTimer",
  "enabled": true
},

{
  "name": "StatsGui-MovementSpeed",
  "enabled": true
},

{
  "name": "stdlib",
  "enabled": true
},

{
  "name": "tarantulator",
  "enabled": true
},

{
  "name": "textplates",
  "enabled": true
},

{
  "name": "Todo-List",
  "enabled": true
},

{
  "name": "TrainModeSwitcher",
  "enabled": true
},

{
  "name": "tree_collision",
  "enabled": true
},

{
  "name": "UltimateResearchQueue",
  "enabled": true
},

{
  "name": "VehicleSnap",
  "enabled": true
},

{
  "name": "WellPlanner",
  "enabled": true
},

{
  "name": "WideChests",
  "enabled": true
},

{
  "name": "WideChestsLogistic",
  "enabled": true
},

{
  "name": "WideChestsUnlimited",
  "enabled": true
},

{
  "name": "YARM",
  "enabled": true
}

]
}

Tried using 6.0.2 with a manual download and received:
Error while applying migration: Extended Vanilla: Personal Equipment: Better-Power-Armor-Grid_4.0.0.lua

...rmor-Grid__/migrations/Better-Power-Armor-Grid_4.0.0.lua:6: attempt to index field 'power-armor-mk4' (a nil value)
stack traceback:
...rmor-Grid__/migrations/Better-Power-Armor-Grid_4.0.0.lua:6: in main chunk

Yeah yeah found the error. Oh jesus my mistakes are endless sorry... xD
_77

Now everything should be okay. Just delete and reinstall the latest version.

Brill thank you - all sorted and working good with the re-install :)