zend_mm_heap corrupted, error 500, error reading data from fastcgi server

[shrtanswr]

I know this error comes up alot for people, but usually because of bad file persmissions and memory/processing/thread limits in their php.ini. I recently hit this error on a new install of whmcs 6.2.2 and whmcs 6.2.1 using ioncube 5.1.2. There's a bug when using ioncube and xcache modules together. It causes ioncube to segfault and you can fix it by removing the xcache module. Took me alot of searching to fgure this out, I hope this helps someone. I had ispconfig on a debian 8 install, where i can installed the apache and the php5-xcache package, before I had started installing whmcs. I know this problem affects other OS's too.

[WHMCS John]

Hi,

Thanks for sharing this information, I'm sure it will prove useful to other users who may encounter the same error.