I have been using BBC Iplayer with no problems for ages. Now, I am having problems on two different computers. One runs on Windows 7 Starter and the other on Windows 10 (upgraded from 8.1). I use Firefox on both. For the last couple of weeks I have been unable to download programs. They appear in iplayer, but then get stuck. The downloading doesn't start. In the log I get the following message;

[WARN]  Unable to find any media that needs to be downloaded.
        Then sometime later this comes up but no upgrade is needed.
[INFO]  Checking local version 1.14.2 to see if upgrade is required
        I've uninstalled and reinstalled BBC iplayer and followed numerous other instructions to no avail.

Can anyone tell me how to fix this problem?

Sorry - you're in the wrong place. You need to contact the BBC. get_iplayer is completely separate from the iPlayer Download application.