assertion failed! Pin_memory problem.

All right. Have you been able to pinpoint in which part of your code this issue happens? Does this happen when you are trying to copy data from the host to the device? Maybe your problem is different from what I encountered on my own environment before; in fact, it seems in your case the DMA operation is failing for some reason. I recommend contacting the support channel of your board manufacturer. They will give you instructions as to how you should obtain debugging information during execution so that they can pinpoint the issue in the driver. If you are using Altera's reference board, then contact Altera directly.