I am running Release 2018-04-22b "Greebo" "on a stick" (MicroApache with PHP 5.6.30) and I installed the elasticsearch-plugin manually and I purged the cache by touching conf/local.php (Installation was not working with the extension manager: "Could not open file for writing: .../dokuwiki/data/tmp/0f0ac169ce9eaeb08ad2f49016507f69/elasticsearch/cosmocode-dokuwiki-plugin-elasticsearch-e4d5fa2/vendor/elasticsearch/elasticsearch/.github/CONTRIBUTING.md.gz"; working with other plugins).
After this manual Installation instead of a wiki page I get the error message
Fatal error: Cannot use isset() on the result of an expression (you can use "null !== expression" instead) in ...\dokuwiki\lib\plugins\elasticsearch\helper\client.php on line 154
Line 154 in "client.php" says
if (isset(self::ANALYZERS[$lang])) return self::ANALYZERS[$lang];
As I have no clue on PHP (and the last change to use of the isset()-command was suppposed to be PHP 5.4), any idea how I can fix this error?
Thanks a lot and best regards,