6644.888 Error MainLoop.cpp:1281: Exception at tick 1228575: The mod PyBlock (0.2.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event PyBlock::on_chunk_generated (ID 12)
Entity name not specified.
stack traceback:
[C]: in function 'create_entity'
PyBlock/control.lua:320: in function <PyBlock/control.lua:189>

local Rocks = {
    'iron-rock', 'copper-rock', 'uranium-rock', 'zinc-rock', 'aluminium-rock', 'chromium-rock', 'coal-rock',
    'lead-rock', 'nexelit-rock', 'nickel-rock', 'phosphate-rock-02', 'quartz-rock', 'salt-rock', 'tin-rock',
    'titanium-rock', 'volcanic-pipe', 'regolites', 'rare-earth-bolide', 'phosphate-rock', 'sulfur-patch',
    'bitumen-seep'
} -- 21 elements

    local SelectedRock = math.random(1, 25)
    local rock = Rocks[SelectedRock]

I'm not sure what lua does in the case of array overflow, but this looks like what's causing the error.

local Rocks = {
    'iron-rock', 'copper-rock', 'uranium-rock', 'zinc-rock', 'aluminium-rock', 'chromium-rock', 'coal-rock',
    'lead-rock', 'nexelit-rock', 'nickel-rock', 'phosphate-rock-02', 'quartz-rock', 'salt-rock', 'tin-rock',
    'titanium-rock', 'volcanic-pipe', 'regolites', 'rare-earth-bolide', 'phosphate-rock', 'sulfur-patch',
    'bitumen-seep'
} -- 21 elements

    local SelectedRock = math.random(1, 25)
    local rock = Rocks[SelectedRock]

I'm not sure what lua does in the case of array overflow, but this looks like what's causing the error.

it would give a nil result or something similar and it would crash as you can see. ill get this fixed. i removed 4 things from the list to be updated to the last pyph and forgot to update the count.

0.2.1 is up and should fix this

Works! Quick question, why not use local SelectedRock = math.random(#Rocks)? It'd always be correct for whatever length of list.