If you have a question, please start a new post with your question. If you reply to a random topic (like the welcome announcement), it's just going to get buried in the comments, which is what happened with the thread you replied to here.
I've branched this out to it's own discussion because I couldn't unroll that random message thread as cleanly as I would have liked, but you can find the answer and ongoing discussion here:
A recent change required for macOS 10.15 results in Flash Player not being able to install on older version of Mac. These older versions of Mac have not been supported for quite some time, although installation was not blocked, this requirement for macOS 10.15 results changes that. If possible, please update to a supported version of Mac - https://www.adobe.com/products/flashplayer/tech-specs.html