Comment 191 for bug 798414

Tex, the command you used failed because of Bug #1678187. However it succeeded to purge many kernels and related packages. But package linux-image-extra-4.13.0-36-generic was not successfully purged technically. What does command 'dpkg -l linux-image-extra-4.13.0-36-generic' print? Anyway, you can now purge the package by 'sudo dpkg --purge linux-image-extra-4.13.0-36-generic', right?

I suppose your original command purged too many packages, as it removed the linux-generic-hwe-16.04 package. You may reinstall it by 'sudo apt-get install --install-recommends linux-generic-hwe-16.04', if you want to continue to get newer kernels via updates. (https://wiki.ubuntu.com/Kernel/LTSEnablementStack#Ubuntu_16.04_LTS_-_Xenial_Xerus)