9.761 Error Util.cpp:81: Error in assignID: entity with name 'nukavan' does not exist. It was removed by Pacifist.

Source: as-per-my-last-email (build-entity-achievement).

Hi, thank you for the report.
To reproduce this, which version of Py are you using and which mods besides it?

lastest mod portal version of py

AutoDeconstruct
BottleneckLite
CleanFloor
Custom-Production-UI-Fixed
Flow Control
FluidMustFlow
InserterCranes-for-pymods
InserterFuelLeech
LogisticTrainNetwork
Milestones
Noxys_Waterfill
Pacifist
Picks-Inserter
PyBlock
RecipeBook
TaskList
VehicleSnap
VoidChestInstant
Warehousing
Wr_Enhanced_Map_Colors
aai-loaders
alien-biomes
alien-biomes-graphics
bobinserters
enable-all-feature-flags
even-distribution
even-pickier-dollies
factorissimo-2-notnotmelon
far-reach
helmod
manual-inventory-sort
miniloader-redux
not-enough-parameters
pyalienlife
pyalternativeenergy
pycoalprocessing
pyfusionenergy
pyhightech
pyindustry
pymodpack
pypetroleumhandling
pypostprocessing
pyrawores
radarplus for rso
rd-fuelmix
show-max-underground-distance
some-autoresearch
squeak-through-2
underground-pipe-pack
underground-pipe-pack_for_py
valves

Thanks. I could reproduce and fix it with version 2.2.10. Please let me know how it goes for you.