Simulating a DDR2 SDRAM or DDR3 SDRAM Controller with UniPHY in version 11.0 controller will result in the following three error messages:
# ERROR: cannot read hierarchy_ram_a.hex. #
# ERROR: cannot read hierarchy_ram_b.hex. #
# ERROR: cannot read hierarchy_ociram_default_contents.hex. #
The hex files are missing from the simulation project directory where the simulation is executed. These errors have no effect on simulation and the simulation will still run without any issues.
The solution is to copy the hex files from the simulations submodules directory to the simulation project directory.
For the controller example design, the simulaton project directory is
core_example_design/simulation/simulation/modelsim
and the simulation submodules directory is
core_example_design/simulation/core_example_sim/submodules.
This issue will be fixed in future version of the Quartus® II software.