Description
Due to a problem in the Quartus® II software, you may see this problem when you recompile the project after changing a Memory Initialization File (.mif) or Hexadecimal (Intel-Format) File (.hex). The updated .mif or .hex files are not read when the compiled database exists, which results in a mismatch.
Resolution
To work around this problem, delete the db and incremental_db directories before recompilation.