I'm trying to run openvibe-designer on my raspberry pie over vnc. Currently I am using Xvnc version TightVNC-1.3.9. All other applications that I've launched over vnc have worked. I only get this error when I run openvibe-designer. Any tips on how to resolve this issue would be greatly appreciated.
X11 is a protocol that has grown quite a bit over the years, and where the natural place to put new functionality was in so-called "extensions". The error message indicates that the program you want to run, uses an extension that Xvnc does not have.
xrandr is an official configuration utility to the RandR (Resize and Rotate) X Window System extension. It can be used to set the size, orientation or reflection of the outputs for a screen.
To my knowledge there is no simple workaround. You can, however, install an X11 server on the computer you actually use and then tell openvibe-designer to use that instead. For ssh connections use
ssh -Y raspberry in a session that has the DISPLAY variable set correctly.