Welcome
It should not have gone into silent mode. If it happened one time, I would think it is due to corruption.
Normal corruption can usually be repaired by a simple boot or using the SFC command, if more serious. http://www.vistax64.com/tutorials/66978-system-files-sfc-command.html
To insure that the cause was not more nefarious, I would suggest a complete anti virus scan
I would also suggest that you download malwarebytes and make a complete and updated scan.