You may receive this critical warning for two of the following reasons:
1) You have not instantiated the Dynamic Reconfiguration Megafunction™ (ALTGX_RECONFIG ) in your design. This Megafunction is required for receiver offset cancelation when your transceiver instance is in receiver only or full duplex mode (receiver/transmitter).
Action: Instantiate the Dynamic Reconfiguration Megafunction (ALTGX_RECONFIG ) in your design
2) You have generated your ALTGX and ALTGX_RECONFIG instances in a previous version of Quartus® II software.
Action: Regenerate your ALTGX and ALTGX_RECONFIG instances in the Quartus II software version 9.0 Megawizard™ Plug in Manager and recompile the design. Once the instances have been updated, the project should compile without this critical warning.