Client API functions return error though they succeed

I am using the function: **testRampSetType(static_cast<uint8_t>(0), ePattern)** from the client API, and get a result  of  **R_SDK_DSPCH_SEQUENCE_MISMATC**H for every ePattern parameter that I input, even though the action succeeds. 

what could be the reason for this? and where can I find the implementation of the client API functions?
