System Extension Blocked Error

[scottydelta]

After installing Karabiner using the link on Github's repo's readme, I started getting this error on system start. Upon going to the security and preferences and then trying to unblock the programs blocked by OS, I don't see Karabiner there but instead I see remains of two other applications I uninstalled recently.

I tried uninstalling Karabiner(manually, then via AppCleaner and then through cleanmymac) completely and reinstalling it, nothing helped. This is what error looks like.