请问以下错误是什么原因

如何解决

谢谢

该错误一直出现，我自己new了一个最简单的project出错，open了一个example也出错，找了一天了也不知道怎么回事

Simulator:607 - ISE Simulator is unable to elaborate this design due to
specific coding constructs used in the design. Xilinx is actively working on
reducing the number of conditions where this error occurs. For more
information on this error, please consult Answer Record 24067 in Answers
Database at http://www.xilinx.com/support.