Flash Player Error at Startup

Hello,

First of all, I gotta say that I have never encountered with this kind of errors when using Chrome. But visitors of my website say videos are not opening, even the player doesn't appear and it shows up a broken tab icon. What should I do to solve this problem? I thought putting an "update your Adobe flash player" warning helps but it didn't work. I will really appreciate your advices at this point, because it's really stuck and I need to fix it.

Thank you.