I do not need a solution (just sharing information)
This morning i've got an overwhelming count of messages from our employees. Many of them were receiving messages that Virus definitions are missing and then some of them have carshed (BSOD) repeatedly 2-3 times. Crash dumps point to MS drivers (mup.sys, fltmgr.sys, rdbss.sys). Makes no sense. Maybe some older fault SEP definition can be the cause and as most has updated already they are not experiencing this issue?