This is just one of the many identical crashes I am getting that seem to involve Oxygen Sealing, Airlocks, Energy Storage Module and the Solar Panels. I am attempting to isolate the issue and will post any more finds I make.
Forge 953, GC 2.0.7.904
http://pastebin.com/5uq1aNd3
2013-12-10 15:33:58 [INFO] [STDERR] Exception in thread "GC Sealer Roomfinder Th
read" java.lang.NullPointerException
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.chunk.Chunk.func_
76592_a(Chunk.java:702)
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.World.func_72832_
d(World.java:559)
2013-12-10 15:33:58 [INFO] [STDERR] at micdoodle8.mods.galacticraft.core.oxy
gen.ThreadFindSeal.run(ThreadFindSeal.java:81)
2013-12-10 15:33:58 [INFO] [STDERR] Exception in thread "GC Sealer Roomfinder Th
read" Exception in thread "GC Sealer Roomfinder Thread" java.lang.NullPointerExc
eption
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.chunk.Chunk.func_
76592_a(Chunk.java:702)
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.World.func_72832_
d(World.java:559)
2013-12-10 15:33:58 [INFO] [STDERR] at micdoodle8.mods.galacticraft.core.oxy
gen.ThreadFindSeal.run(ThreadFindSeal.java:81)
2013-12-10 15:33:58 [INFO] [STDERR] java.lang.NullPointerException
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.chunk.Chunk.func_
76592_a(Chunk.java:702)
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.World.func_72832_
d(World.java:559)
2013-12-10 15:33:58 [INFO] [STDERR] at micdoodle8.mods.galacticraft.core.oxy
gen.ThreadFindSeal.run(ThreadFindSeal.java:81)
2013-12-10 15:33:58 [INFO] [STDERR] Exception in thread "GC Sealer Roomfinder Th
read" java.lang.NullPointerException
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.chunk.Chunk.func_
76592_a(Chunk.java:702)
2013-12-10 15:33:58 [INFO] [STDERR] at net.minecraft.world.World.func_72832_
d(World.java:559)
2013-12-10 15:33:58 [INFO] [STDERR] at micdoodle8.mods.galacticraft.core.oxy
gen.ThreadFindSeal.run(ThreadFindSeal.java:81)
2013-12-10 17:01:15 [SEVERE] [ForgeModLoader] Universal Electricity: Failed to r
efresh conductor.
2013-12-10 17:01:15 [INFO] [STDERR] java.lang.NullPointerException