Flash Player won't install on MacOS

Hi there!

Since a couple of weeks, I've been asked by the Flash Updater to update Flash. Problem is I always get this error message:

This message means "Error: impossible to continue the installation". I have nothing explicit to help me fix the issue. I was wondering if there was some place for installation logs.

Here is my Mac About.

I've followed a few tips from the FAQ and Adobe support but in vain. I've uninstalled previous Flash Players versions. Still no success. I'm just without flash at all now, which can be a pain in the ass sometimes.

Does anyone has an idea?