Happy to help out any way I can
Unfortunately, re-starting the app and trying again did not work for me. I tried it several times, even un-installed and re-installed and tried again. It seems like the downloader does not give the server enough time to respond, as the error message pops up immediately.
Some searching reveals that this must be a common problem, and the solution is simple: download the module, extract it somewhere and set the path in Account > Preferences > Advanced > Others > Browse button. This worked fine.
Is there some some reason VL could not include the TLS module in the package, or make a separate, dependent one?