Can't seem to reproduce it immediately, but it happened right after I pasted a rotated race gate template. I pasted this at the end of a station so it probably crossed uninitialized chunks too.
Stacktrace:
[2015-10-22 18:37:14] java.lang.NullPointerException [2015-10-22 18:37:14] at obfuscated.cL.a(SourceFile:480) [2015-10-22 18:37:14] at obfuscated.dd.a(SourceFile:351) [2015-10-22 18:37:14] at obfuscated.dm.a(SourceFile:378) [2015-10-22 18:37:14] at obfuscated.ch.a(SourceFile:320) [2015-10-22 18:37:14] at obfuscated.ch.a(SourceFile:320) [2015-10-22 18:37:14] at obfuscated.dd.a(SourceFile:1111) [2015-10-22 18:37:14] at obfuscated.ch.a(SourceFile:320) [2015-10-22 18:37:14] at obfuscated.ch.a(SourceFile:320) [2015-10-22 18:37:14] at obfuscated.cP.a(SourceFile:315) [2015-10-22 18:37:14] at obfuscated.ch.a(SourceFile:320) [2015-10-22 18:37:14] at obfuscated.cn.a(SourceFile:228) [2015-10-22 18:37:14] at obfuscated.C.updateStateInput(SourceFile:1322) [2015-10-22 18:37:14] at obfuscated.asT.a(SourceFile:1162) [2015-10-22 18:37:14] at obfuscated.C.h(SourceFile:2767) [2015-10-22 18:37:14] at obfuscated.MT.run(SourceFile:92) [2015-10-22 18:37:14] at java.lang.Thread.run(Unknown Source)