Adobe flash for Linux is outdated/discontiued since years [1]. HTML5 is one kind of replacement, but as you already experienced, it doesn't solve all issues. Your best bet would be to install Google Chrome.
https://chromium.googlesource.com/chromium/src/+/master/docs/chromium_browser_vs_google_chrome.md They still allow to chose 32 bit at https://www.google.com/chrome/browser/features.html , but it results in "404. That’s an error. That’s all we know." Either wait, soon flash will be entirely dead, IOW don't use oldish websites, that require flash, or get a 64 bit architecture computer and hope that Chrome does the job. Assumed your computer should be 64 bit architecture, then simply install a 64 bit release of Xubuntu. [1] https://lists.ubuntu.com/archives/xubuntu-users/2015-June/008414.html -- xubuntu-users mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/xubuntu-users
