Typo3: 500 Internal Server Error

If you get the error message ‘500 Internal Server Error’ when filling out a contact form or opening a link with no_cache, proceed as described below:

Works:
http://www.musterdomain.ch/index.php?id=1

It’s not working:
http://www.musterdomain.ch/index.php?id=1&no_cache=1

Edit /typo3conf/localconf.php and set the following value:

$TYPO3_CONF_VARS[‘FE’][‘disableNoCacheParameter’] = ‘1’;