PTB - ERROR: SYNCHRONIZATION FAILURE and Error Using Screen

Hi.I experienced a problem of PTB-Error: Synchronization Failure when I am using the KbDemo of Psychtoolbox-3 in Microsoft Window 10 Operating System. The following messages pop out when I executed the KbDemo command.

PTB-ERROR: Mismatch between requested display swap interval 1 and actual swap interval 0! Synchronization of Screen('Flip') to display refresh will likely malfunction!

PTB-ERROR: This is either a bug in your graphics driver or system setup, or some misconfiguration in the display setting control panel of your system. See 'help SyncTrouble' for more info.

----- ! 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.

This will seriously impair proper stimulus presentation and stimulus presentation timing!

Please read 'help SyncTrouble' for information about how to solve or work-around the problem.

You can force Psychtoolbox to continue, despite the severe problems, by adding the command

Screen('Preference', 'SkipSyncTests', 1); at the top of your script, if you really know what you are doing.

Error using Screen

See error message printed above.

Error in KbDemo>KbDemoPart4 (line 188)

[ window, windowRect ] = Screen('OpenWindow', whichScreen);

Error in KbDemo (line 93)

KbDemoPart4;

[Walter Roberson]

Psychtoolbox is a third party product . Everything it does with regards to synch and retrace is custom to it using operating system specific dll. The only part of what you posted that is related to matlab is that the Screen() call would be placed in aa matlab script .

You need to follow the debugging steps described in the message . This is not aa matlab issue , it is an os or hardware or graphics driver issue .