ID:11810 Double Accumulator feature is not supported when the Accumulator is disabled. To enable Accumulator, set the "ACCUMULATOR" parameter to "YES".

CAUSE: The specified parameter value is illegal. This error occurs when you instantiate a megafunction directly in a text file.

ACTION: Use the MegaWizard Plug-In Manager to regenerate the ALTERA_MULT_ADD megafunction with a legal parameter value.