In Nintex Workflow Cloud the SharePoint Online - Get A File action needs the name of a Document library to get the file from. One obvious choice is almost always there: "Documents". Especially when linked to a team in MS Teams. Seems an easy pick. But when your site is not all English the URL for the Documents library is in another language while it is still named Documents. This actions seems not be able to deal with that properly.
Example: When - once upon a time - you installed your Microsoft tenant and answered "Netherlands" to the question "In which country is your organisation located?", you're done. All your library names and a lot lot more is suddenly all set to Dutch. Including the language (and folder names) of your teams and a whole lot more. And... it can never be changed anymore. Many know this issue.
In this example the URL for the Documents library of your site is automatically named "Gedeelde documenten".
Unfortunately it seems to me after a bit of testing that the Get A File action is not able to cope with this. And possibly some related actions as well.
BTW. Dear Nintex, please be gracious: if you're updating these actions anyway, can you please also add the error return code option such as for File not found? Currently you just crash the workflow when the file is not found.