(Monster) Mob Spawners throws exception in the develeopment console (lag spike due to spamming)

Just for the sake of specifics this is a non-naturally generating vanilla block that can be spawned in using this command:

/setblock <x> <y> <z> mob_spawner 0 replace {EntityId:"Monster"}

The effect of this block is just the same as any mob spawner, except it doesn't spawn anything at all. It is for all intents and purposes a decoration (mob spawner) block. Unfortunately after about 3-5 of being in close proximity of this block it will dramatically drop your frame rate and cause your client to not respond. My theory is that the block is trying to spawn something in and it can't. This may be the reason behind the lag spikes.

Development Console

23:03:08 INFO]: Client> java.lang.InstantiationException
[23:03:08 INFO]: Client> 	at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(Unknown Source)
[23:03:08 INFO]: Client> 	at java.lang.reflect.Constructor.newInstance(Unknown Source)
[23:03:08 INFO]: Client> 	at wm.a(SourceFile:133)
[23:03:08 INFO]: Client> 	at apd.a(SourceFile:256)
[23:03:08 INFO]: Client> 	at clh.a(SourceFile:19)
[23:03:08 INFO]: Client> 	at clh.a(SourceFile:14)
[23:03:08 INFO]: Client> 	at clh.a(SourceFile:9)
[23:03:08 INFO]: Client> 	at clc.a(SourceFile:121)
[23:03:08 INFO]: Client> 	at clc.a(SourceFile:102)
[23:03:08 INFO]: Client> 	at cij.a(SourceFile:529)
[23:03:08 INFO]: Client> 	at che.a(SourceFile:1196)
[23:03:08 INFO]: Client> 	at che.a(SourceFile:1123)
[23:03:08 INFO]: Client> 	at che.b(SourceFile:972)
[23:03:08 INFO]: Client> 	at bqx.aq(SourceFile:893)
[23:03:08 INFO]: Client> 	at bqx.a(SourceFile:307)
[23:03:08 INFO]: Client> 	at net.minecraft.client.main.Main.main(SourceFile:120)