Just spotted this error on my CentOS7 installation:

[05-Sep-2018 07:09:07 Europe/Rome] PHP Fatal error:  Uncaught Error: Unsupported operand types in /usr/share/z-push/lib/core/topcollector.php:272
Stack trace:
#0 /usr/share/z-push/lib/core/topcollector.php(133): TopCollector->isEnabled()
#1 /usr/share/z-push/lib/request/sync.php(195): TopCollector->AnnounceInformation('Email request', false)
#2 /usr/share/z-push/lib/request/requestprocessor.php(116): Sync->Handle(0)
#3 /usr/share/z-push/index.php(107): RequestProcessor::HandleRequest()
#4 {main}
  thrown in /usr/share/z-push/lib/core/topcollector.php on line 272

Packages installed

# php -v
PHP 7.1.20 (cli) (built: Jul 19 2018 10:10:15) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.1.20, Copyright (c) 1999-2018, by Zend Technologies
# rpm -qa | grep z-push

Anyone else?