1 The "Flush system caches" menu entry is disabled when ``TYPO3_CONTEXT=Production``.
\r
3 You can enable it in the backend user's ``TSCconfig`` settings::
\r
5 options.clearCache.system = 1
\r
7 Also see http://blog.reelworx.at/detail/typo3-cms-clear-cache-buttons-explained/