If you use the "install flash player" function in the chromium add-on settings then it pull the latest version of chrome and uses the flash player from that.
I'm unable to make flash working with chromium, I use the install flash option in the add on setting. I have the last version of LibreElec 7.90.010 Each time I try to access a web page with flash I get a flash message prompt for install. If someone can tell me what's wrong it will be appreciated. Thanks in advance