I’ve faced a big issue whenever tried to update any BackOffice value. It could be product, category or any field from admin preferences. After my modification and saving – the page was still showing old values (those before saving). In this state it is was not possible to make changes in Administation Panel – so it sounds horrible. But I’ve found the reason of that and a solution (for my case).
The answer is Cache…
Hold on! This is not about “smarty cache” which you can configure at the top of Performance page. It’s in the same page, but it’s located at the bottom.
Here is how does it look in PrestaShop 1.6:

And here is 1.7 version:

What I’ve thought was simple – to switch this option off! But… I was still not able to save any data!
I’ve found a soulmate, who posted the same issue in PrestaShop Github:
https://github.com/PrestaShop/PrestaShop/issues/11944. Unfortunately there is no solution given, so I had to look for another solution to set this option to “No”.
Finally I’ve figured out what to do. There is a parameter in PrestaShop config file, which you should change in order to disable this type of cache. I will show you which file and which parameter you need to edit (for both 1.6 and 1.7) to save your BackOffice changes.
PrestaShop 1.6
You have to set value of _PS_CACHE_ENABLED_
to ‘0’.
define('_PS_CACHE_ENABLED_', '0');
Of course save the file after that modification.
PrestaShop 1.7
You have to set value of ps_cache_enable
to false.
'ps_cache_enable' => false,
Then, save the file.
Final changes in BackOffice
After saving a file you can go back to the cache settings in Administration Panel, switch to “No” and save. You will be able to save all values now.
To be honest I’m heavily surprised by this caching system and I can’t understand why does it affect the BackOffice? Something is wrong with that…
Anyway thanks for reading! I hope this article was useful.
Cheers!