SmartyException HTTP 500 Internal Server Error Source: Missing name

[Alonso_Inovum]

Hello, 

I'm developing a e-commerce website based on prestashop (1.7.6.7). The invoice generation of my site worked just fine couple weeks ago, but now the exception

Quote

SmartyException. HTTP 500 Internal Server Error. Source: Missing name

Is triggered every time i try to display/create any sort of pdf document.

 

At first I thought that my modifications had something to do with it, but neither the controller nor any of the files involved in the error's stack trace have been modified... To make sure that my modifications haven't been the cause of this issue I disabled the override folder and the non prestashop modules.

I have also tried to delete and disable the site's cache and it didn't work. I red somewhere that this could be a prestashop's issue. Can someone help me?

Thanks.