Trying to drill on Gleba yields this error note. It appears when the surface drill is supposed to create the tunnel. (reminder that Gleba has no mineable resources other than stone, which doesn't spawn underground)

Error while running event Subsurface::on_resource_depleted (ID 31)
Subsurface/scripts/resources.lua:8: bad argument #1 of 2 to 'pairs' (table expected, got nil)
stack traceback:
[C]: in function 'pairs'
Subsurface/scripts/resources.lua:8: in function 'place_resources'
Subsurface/control.lua:237: in function 'clear_subsurface'
Subsurface/control.lua:521: in function <Subsurface/control.lua:507>

I tried to fix that myself but I have no idea what to do.

Addition: I tried this isolated and it does happen. I also installed all the planet mods I could find, and the result was one: Only Gleba is broken, even SS++ planets based off of Gleba work normally.

Edit: Tried to dredge the "planet" Neumann from the mod Metal and Stars, which doesn't have mineable resources at all (so it doesn't have resources to spawn in the subsurface, like Gleba), and it crashes with the same error.

Could you replace line 8 with the following and try again:
for proto, _ in pairs((surface.map_gen_settings.autoplace_settings.entity or {settings = {}}).settings or {}) do

Will try as soon as I get home

Sorry for not replying for so long, dang I thought I did reply
It works perfectly with the line you provided