Hi!

I'm using nigtly build of recurrent complex and ivtoolkit n139 and n85, forge is at latest recomended for 1.7.10, I created a spawn structure using reinforced blocks by open modular turrets mod, a garage door by malissis doors and some basic turrets (from open modular turrets). I've set to "spawn" the structure at spawn with a Y shift of 80 because it has a deep dungeon underneath, here is the crash:

http://pastebin.com/MfWrAvkX

I'm going to spawn a small build made with vanilla blocks and without y shift to be sure if the building blocks are the problem.

Thank you so much for your time.

Would have been nice to get some feedback on this.

I'm going to have a look at it for the next release. I haven't been able to work on ReC in quite a while, but I should be able to fix this within a month or so now.

I'm pretty sure the problem is the size, here. I've encountered a similar error, and the only way I could get it to stop (after closing client, disabling mod, opening client, loading map, closing client, re-enable mod, re-open client) was by limiting the size of the gen-zone. Turns out the zone is ridiculously small (in my terms, anyway. I can't possibly have more than a 50 x 50 x 35 area). Is that normal?

Your structure was spawning too low. Now it will spawn, although the problem that part of it might get cut off from spawning too low remains. I recommend keeping a look out for #45, which will allow you to specify this as a spawn condition ('enough space remaining to bedrock').