When placing a corner block, I noted the following error always posts to the server log.

[15:53:53] [Server thread/FATAL] [FML/]: Exception caught executing FutureTask: java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: javax/vecmath/Matrix4f
java.util.concurrent.ExecutionException: java.lang.NoClassDefFoundError: javax/vecmath/Matrix4f
at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_51]
at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_51]
at net.minecraftforge.fml.common.FMLCommonHandler.callFuture(FMLCommonHandler.java:715) [FMLCommonHandler.class:?]
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:656) [MinecraftServer.class:?]
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:364) [po.class:?]
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:598) [MinecraftServer.class:?]
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:478) [MinecraftServer.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_51]
Caused by: java.lang.NoClassDefFoundError: javax/vecmath/Matrix4f
at com.hea3ven.buildingbricks.core.blocks.BlockBuildingBricksCorner.getBoundingBox(BlockBuildingBricksCorner.java:82) ~[BlockBuildingBricksCorner.class:?]
at com.hea3ven.buildingbricks.core.blocks.base.BlockBuildingBricksNonSolid.func_180640_a(BlockBuildingBricksNonSolid.java:49) ~[BlockBuildingBricksNonSolid.class:?]
at net.minecraft.world.World.func_175716_a(World.java:3145) ~[aqu.class:?]
at net.minecraft.item.ItemBlock.func_180614_a(ItemBlock.java:61) ~[aju.class:?]
at net.minecraftforge.common.ForgeHooks.onPlaceItemIntoWorld(ForgeHooks.java:568) ~[ForgeHooks.class:?]
at net.minecraft.item.ItemStack.func_179546_a(ItemStack.java:132) ~[amj.class:?]
at net.minecraft.server.management.ItemInWorldManager.func_180236_a(ItemInWorldManager.java:446) ~[qx.class:?]
at net.minecraft.network.NetHandlerPlayServer.func_147346_a(NetHandlerPlayServer.java:595) ~[rj.class:?]
at net.minecraft.network.play.client.C08PacketPlayerBlockPlacement.func_180769_a(SourceFile:59) ~[mx.class:?]
at net.minecraft.network.play.client.C08PacketPlayerBlockPlacement.func_148833_a(SourceFile:10) ~[mx.class:?]
at net.minecraft.network.PacketThreadUtil$1.run(SourceFile:13) ~[ih.class:?]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_51]
at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_51]
at net.minecraftforge.fml.common.FMLCommonHandler.callFuture(FMLCommonHandler.java:714) ~[FMLCommonHandler.class:?]
... 5 more