Unity 5.5.2 won't load, but runs as a background process in the task manager...HELP.

So, I recently upgraded from Unity 5.5.1 to 5.5.2, and it was previously working fine, at least for the most part. However, when I upgraded, I would try to run Unity, but nothing would happen. I looked in the task manager, and it still wasn’t their. However, I chose more details and scrolled down to the background processes, where, for whatever reason, Unity was running. I cannot use unity at all. Please help.

First check editor.log file located to user–> app data–> local data–> editor.log file open .
Check last 5 line of the editor.log file
Show An error unity shader compiler not initialisation at the time… please remove the antivirus in the system or remove the file in antivirus software in reports.

Same problem for me and I’m using Unity 2017.2.0 (64-bit) version.
Some determine it has something to do with antivirus software.

One of the solutions is working offline.
Didn’t work for me, sadly.