In FTD2XX library FT_open() results in segmentation error

  c++, dll, ftdi, tcp

during execution of FT_open() function in my c program it results in segmentation error

when I execute the program from root user it works fine but I get the above error when I execute from other users

FT_HANDLE ftHandle; FT_STATUS ftStatus; 

ftStatus = FT_Open(0,&ftHandle); // segmentation error occurs when executing this line!!
if (ftStatus == FT_OK) 
} else { }

please help!!

Source: Windows Questions C++