UPBGE warning me about "registering" the same object multiple times?

Simply put, if I add multiple objects (usually many of them), UPBGE tells me that I am trying to “register” the same object several times.

It usually is a warning in the console that says: “Warning: You’re trying to register the same Object several times”

But I see no adverse effects on the Game Engine, and no crashes. So, why was this console message added? There is also no yellow text that indicates a warning.