Blank screen (Cache errors) after upgrading php from 5.3 to 5.4 | Prestashop 1.6

[flamedtofu]

Hello,

 

I manage my own VPS server that hosts prestashop and I decided to run some updates including upgrading php to 5.4. however I failed to disable caching on my store before the upgrade, which I now believe was the root of my issues, duh.

 

After the upgrade I just received a blank screen on both the front page and PS backend, after turning on debugging mode I got errors like Fatal error: Call to undefined function apc_cache_info() in prestashop

 

I then followed some guides that suggested to mainly clear the cache via ftp

which I deleted everything from these folders

prestashop\cache\smarty\compile
prestashop\cache\smarty\cache
prestashop\themes\mytheme\cache

 

After this I received another error

Fatal error: Class 'Cache' not found in /home/occasionhamp/public_html/classes/db/Db.php on line 510

at this point I decided to try and tun off caching to see if that could let me into the backend, to then clear it from there before enabling it again.

I tried to turn caching off from phpmyadmin but failed to see how, I then found a guide that suggested 

edit the file /config/settings.inc.php changing the following line:

define ( '_PS_CACHE_ENABLED_' , '1 ' );

by
    
define ( '_PS_CACHE_ENABLED_' , '0 ' );

after this I now get the following error and have no idea what to try next:

Fatal error: Class 'Cache' not found in /classes/ObjectModel.php on line 1584

 

My other sites hosted on the same server (wordpress) work fine after the upgrade, any ideas on what i can try next, I suppose ideally i'm looking to either, properly clear the cache on my site, or turn caching off via phpmyadmin or ftp.

 

also would you expect upgrading the php version with caching turned on to cause this error?

 

I am running PrestaShop v1.6.0.14

 

Massive advance thanks

Edited May 17, 2015 by flamedtofu (see edit history)