Opera is cool browser. Maybe a bit behind Chrome and Firefox but definitely better than Internet Explorer. But that doesn’t stop certain sites filled with obsolete code to prompt you to switch to IE or Firefox from Opera in order to view their content.
However, as I already mentioned that Opera is a great browser, it’s intelligent enough to deal with such kind of scenarios. You can easily mask Opera as Internet Explorer or Firefox for certain websites and fool them into thinking that you are actually browsing through one of them. Cool, right? Lets see how it is done.
Fixing Compatibility Issue
Whenever you are on a page that shows you the error that you must shift to Internet Explorer or Firefox, open Opera menu and navigate to Settings—>Quick Preferences—> Edit Site Preferences.
In Site Preferences settings window, open the Network tab and select Mask as Firefox or Mask as Internet Explorer from the Browser identification dropdown settings. Finally save the settings and refresh the page that’s giving you the error.
The page will reload without showing any browser incompatibility error. There’s an option of identifying as other browser as well, but masking always works better when you need to pass these kind of issues.
So next time some annoying website is freaking you out for compatibility reasons while browsing on Opera, no need to switch to a different browser anymore.