Some websites no longer support Opera 12. For instance google.com shows up in a not useful way in Opera 12.
Sometimes a user script is good enough to fix it, if the website sends the same code to every browser and the selections is made by JavaScript (look example below).
Some websites, like Google, send different versions of the code for different
browsers, though. So the spoof must be done by the browser itself. Opera 12 has a feature to do it for every site separately: right click menu | "Edit Site Preferences" | Tab : "Network" | "Browser identification" | Choose: "Mask as Firefox" or "Identify as Firefox" (or IE). It used to work well, but Opera 12 is no longer updated, so the hardcoded choices of "User Agent" strings are obsolete. The old versions of Firefox and Internet Explorer are no longer supported by many websites.
So the "User Agent" spoof choices which are hardcoded in opera.dll must be updated.
What's needed is a hex editor.
