Did you encounter any problems/massive false alarms regarding OPcache activation?
A short time after I activated (for the first time) OPcache for my site, Wordfence reported 22 critical issues in various folders (themes, plugins, uploads) – even in/wp-content/plugins/wordfence/!
For all files the same diagnosis:
“The text we found in this file that matches a known malicious file is: “\x00″. The infection type is: Javascript code indicative of malware.”
I hope this could have been caused by OPcache activation and is not harmful?