If for any reason you need to download and transfer a Pro Line Fusion or Pro Line 21 charts database again in Jeppesen Distribution Manager (e.g. to change an coverage subset for a trip), you don't need to reach out to Jeppesen Support to have the 'Transfers Remaining' reset. You can press "Transfer To Device" an unlimited number of times:
Even though it may say "Transfers Remaining: 0," you still have the ability to update the charts. As long as the "Transfer To Device" button is highlighted, charts can be transferred to a USB stick or drive.
However, if for some reason the "Transfer to Device" button is NOT highlighted or you're unable to transfer the charts, you can "Clear Cache..." in JDM and the download will return:
Simply log back into JDM with your Jeppesen credentials and attempt the transfer process once more.