TYPO3 v8 has reached its end-of-life March 31st, 2020 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
Reference to a file in the file system:*
If the value contains a "/", it is expected to be a reference (absolute or relative) to a file in the file system. There is no support for wildcard characters in the name of the reference.