My hosting company recently installed MultiPHP to enable PHP 7 support on newer C5 Version 8 sites under my VPS account (Linux CENTOS 6.9 / WHM v68.0.39).
Since that point any Concrete5 5.6.x sites have been "broken" (they're running PHP 5.6). The editor toolbar no longer shows up when trying to edit the page - basically "bricking" the site. Browsing the dashboard works mostly (occasionally getting "access denied" errors in the sitemap). I've tried disabling Cloudflare in case that was related, but no effect.
The only other info I could find about this on the forum was this post:
I've tried changing the PHP handler from suphp to cgi with no difference. Also tried enabling PHP-FPM with no difference (although the site loaded faster).
Does anyone else have any problems running MultiPHP and C5?
Have tried setting the php version for a particular installed C5 version that works in your htaccess file?
Definitely seems like MultiPHP isn't playing well with C5.6.x.
In the update from easyapache 3 to 4, the "tmp" folder location is changed by default. There's a new temp folder for each version of PHP installed on the server (so if you change php versions the temp folder changes). Ensure correct permissions are applied.
There was a second cause to my issue - I had an SSL certificate installed on the site which wasn't be used (I had too many links pointing to the http version and needed time to switch). However once I made the https version the "live" one, everything started working normally. It looks like easyapache 4 expects the ssl cert to be used if it's installed and won't correctly store the session data - that's my assumption.
Hope this helps anyone struggling with this issue.