the glReadPixels call fails when I try and read from a texture buffer or a frame buffer. I have submitted the details in a separate discussion. The code used has been checked by the Intel development and confirmed OK (other than some checking)
The Driver is raising an OpenGL debug message and an OpenGL error is set.
There are two other discussion also with glReadPixels fails when reading from a buffer other than the main default Windows buffer.
Please see the links below