Map download failes: Invalid key or download temporarily unavailable

I tried to set up openmaptiles-server via docker. Sadly I get an error message when trying to download a map in the installation wizard.

Here is what I have done:

• I am at the last step of the wizard: "Publish" I get the key from the website, paste it into the wizards input box, click "start the download"... container log says:

Downloading osm-2018-09-24-v3.8-europe_germany.mbtiles (europe/germany)

Downloading: 2247 of null 0.00%

Download done!

• Then i get the following error message in the browser: "Invalid key or download temporarily unavailable!"

Im sitting behind a router. Do i have to forward any ports? What am i missing?

I came across this today and found that you need to actually create an account on Open Map Titles and log in before creating the key. It is a bit confusing that you can generate a key without creating an account and the generated key is invalid.

Also found that you might need to restart the docker container the server is running in as well as I got caught in a loop with the server trying to continually download the requested MBTiles with the invalid key.