Upgrade to El Capitan, unable to use keyboard and trackpad after sleep

Ok I can confirm that the keyboard and trackpad are stuck after sleep when I let VMWare Fusion running... If you have something similar that's running in background it could be the problem.

To resolve it at the moment I pause all Virtual Machines and everything goes alright now.

This is probably related to kernel modules installed by VMWare but I can't find any clue...

If you don't want to reinstall, why not run the installer against a clean external USB drive. Does the trackpad work there? Does the trackpad work when you boot to the Recovery HD?

Those two things will tell you if you have a hardware issue (trackpad won't work anywhere) or a software issue (trackpad either will work in a new user account and not your specific user account) or a system issue (works in Recovery HD but not in your current system.

Based on where the problem lies, the solutions depend. You don't need a hardware repair if it's software and the software repair changes depending on what isolation steps pass.