From what I see, this seems to be the problem:
PrestaShop\PrestaShop\Adapter\Presenter\Cart\CartPresenter->present(NULL)
In assignGeneralPurposeVariables() method, the method that causes you the error is called
'cart' => $this->cart_presenter->present($this->context->cart)
and $this->context->cart is null
The assignGeneralPurposeVariables() method is called in init_content(), but in init(), this->context->cart is initialized.
Between init() and initContent() the actionFrontControllerAfterInit hook is executed, I think of a module that acts on that hook, overwrites $this-context->cart, and makes it null.