Now and then we come across a site that does not want to collaborate with Opera. This section of the Wiki will attempt to give a few hints about how one can pinpoint the problem, where to ask for help and - if applicable - how to file a bug report.
When accessing a web site you are taken to a page saying "upgrade your browser", "please download Internet Explorer to use this site" or similar.
This is a slightly "kinder" form of the above - the website gives you access but detects Opera and thinks "oh, this browser probably can't show my fancy menu so I will just disable it". This is a very common reason why things do not work and is often related to commonly used scripts not being updated.
Oh yes, if something doesn't work it may also be a bug in Opera...
If something doesn't work, these are the first things to try..