I have question or more what is the best practice for a problem.
I have users uploading versions of documents (mostly PDFs) that are linked to on other pages and across other portals within the same installation. The file name changes with the version number and is important ot make sure users have the up to date document version.
I prefer to create a permanent link to a document and have admins upload the last version of the document to that link - so that the link remains unchanged. All other links pointing to this document remain unchanged. What is the best practice for this? Is there a module or solution for changing document versions but not having to update multiple links to the document? Thanks in advance.

Presumably the links to the document point to a specific URL and a specific file. You might try making the links point to a shortcut that points to the current version of the file. I have no idea if this will work, and it seems like a maintenance mess. But, it would not require that you edit links. You'll just have to edit the shortcut each time somebody uploads a new version.