Sorry for hijacking the thread, but chris described the issue so well that I might as well piggyback. Again, I’m experiencing everything he described. I have also gone through the various steps of troubleshooting.
Essentially, activating the 3.3.4 version of woocommerce generates the 500 error both on the frontend and backend. Removing/renaming the woocommerce folder via FTP resolves the error, so it’s clear the issue is with woocommerce.
My temporary url is: https://0180eff.netsolhost.com/wordpress2018/
I am leaving woocommerce activated for the next 24 hours so you can see the error for yourself.
I imagine you will get many more similar support requests as people update their woocommerce to 3.3.4.