Error: file one or more time limited megafunctions

Hello,

I am working with DE2 development board and I am trying NIOSII for the first time and when I am trying to burn my code to my board it gives an error "contains one or more time-limited support megafunctions That the OpenCores Plus That feature will not work after the hardware evaluation time expires. messagges reffering to the evaluation time window for details ".

I have read certain of the threads referring to this and accordingly I am using Nios II/e but still I am getting the same errors. (I have generated and also compiled the entire code, still I am having the error)

Note: I am using the following components along with the NIOS processor:

1) jtag_uart

2) on chip memory

3) PIO

4) clk

can anyone please help me with this