Which version of Opera? And flash?

I have version 25.0.1614.68 of Opera. And my Flash is the most recent version.

Today, I was having trouble with YouTube and a few other websites that use Adobe Flash Player. Videos stopped playing and started displaying errors in the middle of viewing. On most refresh attempts, the errors would occur without end. I decided to turn off the plugin, and turn it back on, because that usually solves the problem. Unfortunately, when I went to the plugins page, Adoby Flash Player was nowhere to be seen. I know that I didn't delete it. I never delete useful plugins. Would someone kindly tell me what's going on please?