[Trisquel-users] Re : Gnash Won't Play Certain Flash Content

Flash plugins execute programs written in the ActionScript programming language. ActionScript can be decompiled but it often is obfuscated, i.e., the source code is inaccessible and the programs are proprietary, an injustice. https://trisquel.info/en/wiki/play-videos-without-using-flash

[Trisquel-users] Re : Gnash Won't Play Certain Flash Content

See https://trisquel.info/en/wiki/play-videos-without-using-flash for solutions on many (not all) websites. I happily use ViewTube and ViewTube+ and when it fails, I try UnPlug.