Unable to intall GuestAdditions and use shared folder

I have install Ubuntu server Version 14.04.3 on as a guest on windows 8.1 upgraded to windows 10 using oracle Virtual-box 5.10 . I have updated the guest os as usua, and installed
and mounted the file virtualBoxGuestAddition.iso file at my home directory. When I run the installer for the Linux version , I get the following errors

1. The headers for the current running kernel were not found. If the following module compilations fails, this could be the reason
2. Building the share module fails.(Look at /var/log/vboxadd-install .log to find out what went wrong).