Failed to open stream: Too many open files


I am new with SuiteCRM, however I have been able install it correctly so far. However, I keep on having the same error message when I want to save leads/contacts…And I do not know how to fix it:

Warning: require_once(/Library/WebServer/Documents/SuiteCRM/modules/AOD_Index/Lib/Zend/Search/Lucene/Storage/File/Filesystem.php): failed to open stream: Too many open files in /Library/WebServer/Documents/SuiteCRM/modules/AOD_Index/Lib/Zend/Search/Lucene/Storage/Directory/Filesystem.php on line 349

I am running SuiteCRM on my MacBook Air (localhost). High Sierra, MySQL & PHP. I have been looking for step to step instructions on the web unsuccesfully.