LabVIEW crash

Hello,

I am trying to program an application for a  FPGA, spartan 3 board from Opal Kelly. I am using their okFrontPanel.dll to initalize their FPGA XEM3001v2 device.

While initalizing I am calling a function openby_Serial with an empty string. 

LabVIEW crashes whenever I run this VI.

I am attaching the VI and the screen shot of the crash.

Please suggest a solution

Thanks

Akbar Doctor