I would have asked do you have 65 documents and 82 Users assigned but that does look a lot of documents. I wonder if you have some orphaned documents which are taking some licences. If you look on the Management console at the documents folder structure (cant recall whether its user or source but this issue may be if you have server only so there will probably be only one document area) there may be a folder called something like orphans? Open it up and if there are documents in there (possibly 17 = 82-65 ?) they may be taking some of your licences. This happens when documents are deleted on the server without releasing the licence first.I think you need to restore them before you can release the licences. It may be worth a look round the community how to do this.
If this is not the issue, you may have a corruption issue perhaps with the licence PGO file. That may require a chat to Qlik support.