PrestaShop CacheMemcached Disabling

We enabled the Memcached PrestaShop couple of months ago by following thee instructions

Now we need to upgrade PrestaShop to Latest version with 1 click upgrade that requires to Disable Caching. When we disable the caching it is causing the HTTP Server error and entire prestashop admin doesn’t work. We are motorcycle related business and cannot afford very website going down if we upgrade.

Please advise how the server is not handling it properly.