Fishing while Redstone Repeater spamming Activate Command Block Crash

I build Fishing Area and when I try to Fishing, Crashes.

Description: Executing command block

java.lang.NullPointerException: Executing command block
	at rv.a(SourceFile:324)
	at p$1.a(SourceFile:188)
	at p$1.apply(SourceFile:185)
	at com.google.common.base.Predicates$AndPredicate.apply(Predicates.java:359)
	at com.google.common.base.Predicates$AndPredicate.apply(Predicates.java:359)
	at aia.a(SourceFile:2283)
	at p.a(SourceFile:490)
	at p.b(SourceFile:143)
	at k.a(SourceFile:51)
	at ahp.a(SourceFile:114)
	at aku.b(SourceFile:96)
	at lr.a(SourceFile:645)
	at lr.d(SourceFile:216)
	at net.minecraft.server.MinecraftServer.D(SourceFile:618)
	at net.minecraft.server.MinecraftServer.C(SourceFile:554)
	at bzg.C(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:458)
	at java.lang.Thread.run(Unknown Source)