aarch64 instruction

I have a build problem when use aarch64 instruction. I use ds5 for simulation,  

target CPU: Generic ARMv8-A AArch64

target FPU ARMv8(NEON & Crypto)

others use default

UMOV      w5, v3.h[#2]

index #2 have 2 errors

error: unknown token in expression

error: unexpected token in argument list

when I changed other instruction with index, like INS       v3.8h[#2], w5, it has the same error.

Can somebody help me? 

Thanks.