Error in vis_stream at line streamnames = find_streams(lib);

[arjangahmadi]

Hello all,
I am new in this area. I have one issue regarding using vis_stream. i have an error at line of streamnames = find_streams(lib);,
although I could run build_mex.m and lsl_loadlib(), I couldn't understand, why i can not run this "streamnames = find_streams(lib);"
I would say, my device is connected and i can see the Raw data in EmotivPro software.

Thanks in advance for your