Congratulations! You are the first person to report this bug that I know of. 
I fixed it two weeks ago and thought to myself: “Wow, nobody has reported that yet, even though it has been broken for a very long time.”
Anyway, that fix isn’t available yet, since it is part of a big overhaul of the backup and restore process. You can either wait a couple more days until it’s done or try the following workaround:
- Extract the backup file
- Open the
meta.jsonfile and remember the value of “version” (in your case20160405172827) - Delete the
meta.jsonfile - Create a new gzipped archive with the rest of the extracted files and folders and make sure the filename ends with the version number from the
meta.jsonfile. In your case it could look like this:discourse-2019-12-10-010038-v20160405172827.tar.gz - Try restoring that backup file. It should work.