As soon as i launch the first rocket with science packs loaded the game crashed with the following error

the only mods i got active are:
Simulacruis
Squeak through2
infinite ressources

The mod Planet Ferrum (0.0.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event planet-ferrum::on_rocket_launched (ID 14)
'inventory index': real number expected got nil.
stack traceback:
[C]: in function 'get_inventory'
planet-ferrum/scripts/pedestal.lua:254: in function <planet-ferrum/scripts/pedestal.lua:251>

I just ran in to this problem. I fixed this instance and it let me launch the rocket and claim the research.

In scripts/pedestal.lua

replace this line:
local cargo = rocket.get_inventory(defines.inventory.rocket)

with this:
local pod = rocket.cargo_pod
local cargo = pod and pod.valid and pod.get_inventory(defines.inventory.cargo_unit)

Thanks Loftaris, it worked. Great fix!

Included in the new patch. Thanks Loftaris for the stopgap!