,This is likely because you used the console command “Stat StartFile” by accident. Using the console command “Stat StopFile” will fix this. Don’t just hide the messages! (open console by pressing ~).
If you are actually profiling your game (in standalone window) and still want to remove these messages do this:
Click the drop down beside the play button at the top of the UE4 editor → Advanced settings → scroll down to “Play in Standalone Game”. Inside “Additional Launch Parameters” paste -NOVERIFYGC -NOAILOGGING
I realize this is an old question but might help other with a similar issue.