I did not recommend it. If you accually read my post you should be able to understand that my post is a copy & paste of whats new in version 2.6.0.
Take it easy!
This module works fine for me, so try that one
https://www.nulledfrm.com/threads/pdf-invoice-template-delivery-custom-number-module-v1-3-1-latest-by-globo.18839/
If you rely need 7.9.2 its here:
https://www.nulledfrm.com/threads/module-jpresta-speed-pack-7-9-2.36216/
Otherwise the latest version 7.9.11 is here
https://www.nulledfrm.com/threads/module-jpresta-speed-pack-7-9-11.41023/
I use Product Catalog (CSV, Excel) Import (by MyPrestaModules).
It works fine for me, but I haven't tried the cron function.
You'll find the module at
https://www.nulledfrm.com/threads/myprestamodules-product-catalog-csv-xlsx-import-6-5-3.37955/
Perhaps you could try another checkout.
Take a look in the settings for the theme Warehouse. If there is a setting for Maxmind, geoip or something like that, try to disable it.
Probably both the theme Warehouse and the module SuperCheckout use the same the same class name, or both the theme and module use maxmind.
I'm not sure whats the best solution to solve it would be.