Flash doesn't load in Chrome browser. Says "Couldn't load plugin."

I noticed that while HTML5 videos work fine, flash videos do not load. I have researched this and have tried numerous things to no avail.

1) I've tried uninstalling/reinstalling Chrome (deleting everything, even the Google folder in localappdata).

2) I've tried disabling/enabling Adobe Flash Player from chrome://plugins/

3) I've tried resetting all settings from chrome://settings/

4) I've tried disabling all extensions.

When I uninstall and then reinstall Chrome, however, the problem goes away. I am able to view flash videos. But when I sign into Chrome and have all of my bookmarks, settings, and extensions synced automatically, the problem comes back.

Below is the list of extensions I use:

Empty New Tab Page

Google Docs Offline

History Eraser App

Mailto: for Gmail™

Reddit Enhancement Suite

uBlock Origin

What could be the issue?