Having trouble with Eyelink

Hi,

I tried to run some Eyelink demos, but none of them works on my computer.

I constantly getting 

'----- ! PTB - ERROR: SYNCHRONIZATION FAILURE ! ----

 

One or more internal checks (see Warnings above) indicate that synchronization

of Psychtoolbox to the vertical retrace (VBL) is not working on your setup.'


message whenever I tried to run it. If I try to run it by ignoring the error message I do get exclamation mark in inverted triangle like this http://i.imgur.com/r0adk7E.jpg.


 

The message and image does not appear when I try PsychToolBox demo files (e.g. DotDemo.m). 





I do have most recent PTB, Eyelink, Matlab versions, and my computer specifications is 


-Windows 10

-i7-6600U Processor

-Intel HD Graphics 520 & NVIDIA Maxwell Architecture Custom 1023 MHz GPU (Surface Book dual GPU / I tried to use it with single GPU by running the Eyelink demo files on Tablet mode)

 


I do really appreciate your help, Thanks.