I'm only using it on Vivaldi browser (Chrome). In the browser's settings select always allow flash. Uninstall the version of flash player you have in programs and features.
In the flash player download page select 'need flash player for a different computer', In the new window select your operating system, in the version box select' FP 25 for Opera and Chromium PPA-PI, untick the two optional offers. Download and install. . Then close and reopen the browser.