Windows Defender Advanced Threat Protection seems to cause a perpetual need to rename a list of files on each and every boot. Each re-boot this list to be re-renamed is re-built and software install's that check for pending reboots will fail and ask for the system to be rebooted only for the entire situation to re-arise once it's been re-booted.
This same message has been posted on another board and was referred to this one, so here it is.
@Ruud_Hakkesteegt, please open a Microsoft CSS Support case. In the M365D portal (security.microsoft.com), click on "Need help?" -> Search -> click on "Contact support", and fill out the form. Thanks, Yong Rhee [MSFT]