After upgrading to version 8.1.2 my checkout does not even work

[PushyMr]

Hello! I recently upgraded prestashop from 1.7.8.2 to 8.1.2 and have multiple issues, one of the main issues that I encountered that the checkout in my front store is not working anymore and i am getting this error when i have a dev mode on

for more context - this happens when i try to procceed to the checkout where the client would need to start filling in Name, adress, shipping and payment, the whole checkout page seems to not open. 

I checked what controllers i have that could be related to the issue, and since we use order manager module made by prestahero it controls a looooot of our website, but i get this error with it on and off, so it might not be related to it, as for the controllers - the ones related to the front store that i have are - 

controllers/front/OrderController.php

override/ps_core_files_for_ets_ordermanager/src/PrestaShopBundle/Controller/Admin/Sell/Order/OrderController.php

classes/controller/FrontController.php

 

I DO NOT HAVE an override for front order controller anywhere (and i did check with our previous version and it didn't have it either)

I am also attaching a log from dev mode, in case you people would notice something, and noter my order manager module, stopped working even though the version that i have installed according to dev change logs SUPPORTS pretshhop 8.1.2

dev-2024-10-24.log