If you don't have error on log file, you will find error message in apache error log file.
Most common errors are :
- zip module not installed
- access rights don't give write acces to target folder (projector/plugin for download whole projector folder for install)
this is the message on Apache error log file
[Mon Oct 09 09:09:40.383072 2017] [:error] [pid 16051] [client 192.168.100.100:49335] PHP Fatal error: Call to undefined function curl_init() in /var/www/projeqtor/plugin/installAuto/installAutoZipList.php on line 100, referer: http://192.168.100.200/projeqtor/view/main.php
You must install php_curl on your php.