Firefox 8 / 9 keep getting non-supported browser error

Error Message when accessing Google+

Firefox 8 / 9 keep getting non-supported browser error when access Google+ or Gmail.

This is most probably due to the useragent string that is mess up by the add-on.

Error Message when accessing Gmail

Below is the solution:

type about:config in the URL bar and hit Enter
If you see the warning, you can confirm that you want to access that page.
Filter = general.useragent.overide
Right-click the preferences that are bold, one line at a time, and select Reset.
Then restart Firefox

source link

Disable Chrome Print Preview

Disable Chrome Print Preview
Command: about:flags




- Search for 'Print Preview'
- Click 'Disable'
- Re-launch browser

That's it!