Vivado Simulator and ModelSim do not work out of the box when simulating designs created using the "Open IP Example Design" option in the Vivado GUI. This is because the memory models required for simulation have required define statements which are not sourced in the "Open IP Example Design" flow.
Solution
To work around the issue you must run the xsim_run.bat/.sh, or sim.do located in the ./example_design/sim/ directory of the generated IP. The "+define ..." options located in the *.prj orsim.do can also be added into the Vivado Simulation dialog box alsoto work around the issue.