My last resort would be an in place upgrade to the same version. Download the ISO using the media creation tool, mount the ISO using right click and run setup to repair the complete system. The other option is a system reset but you will lose installed applications, in place upgrade just repairs the installation without changes.
www.uno.net.uk & freenetname
Asus RT-AC1200G+ and ZyXEL VMG1312-B10A Bridge on 80/20 Meg Fibre
Current Sync: 79993/19661