I believe the simulation designer used the ,severity level message "failure", as a simulation control variable. When this variable is used modelsim will issue a simulation break.
Believe it or not this is a successful completion of the simulation. You should also get a "query box" asking if you want to quit. Answer no if you want to view waveforms or any other information about the simulation.
Answering yes will cause modelsim to close.
If you look at line 1029 of test_interface.vhd you will see that this is the end of a successful simulation.