Typo3 and RealURL

I use various sites with Typo3 and RealURL extension. Mysteriously, it sometimes happens that links at the frontend do not work after updating Typo3 itself or any extension. Problem detection is very complicated because RealURL has a very hidden and strange behaviour. Even worse: it seems that there is no rule on what links can be decoded and what not.

Main things you have to do if you get “segment X ist not a postVarSet variable” error:

  1. Make sure you are logged off from the backend
  2. Make sure you give RealURL a chance to fill the path cache by clicking in your frontend from top to bottom!

What internally happens is as follows: Once the path cache is emptied, it will be filled again only when you are logged off from backend. I have no idea why RealURL implemented this feature but it has a special condition check before updating the cache that makes sure the user is not logged into the backend.

Furthermore, cache update happens only when “Encoding” takes place (ID to path translation). That means that you will get the postVarSet error when you try to get a page from your frontend before RealURL did encode it. That’s why you have to click “down” your website from top to bottom, so all links are created before they are ever requested by your browser.

So next time just follow this two simple rules and your RealURL extension will behave as expected.