what is CL_INVALID_KERNEL ?

Hi,
I am getting error -48 which is CL_INVALID_KERNEL after a call to clEnqueueNDRangeKernel. I went to the documentation to find out what this means and am told “kernel is not a valid kernel object.” which is basically a tautology to me? Could anyone help me begin to work out what the reasons might be?

Interestingly, if I compile on my Intel CPU the kernel runs fine. I only get this error running on my Nvidia GPU, which also returns Segmentation fault (core dumped).

Thanks.

Did you check for an error return from clCreateKernel? Perhaps the kernel was not successfully created.