Hi Ronald,
This is my fault. I recently updated the block so that instead of having a single admin setting for the username & API key to link to the OppiaMobile server, I tried to make it more flexible so whoever is logged in can specify which OppiaMobile server they'd like to link up to. (for example, some of the courses I have on our Moodle are for different OppiaMobile instances - so now I can select which server to export to).
However, this means that each moodle user currently needs to specify the OppiaMobile server, username and API key to be used. For your account on our Moodle, I've already added the connection data to the
demo.oppia-mobile.org server - so it should all work now. If you want to have the course quizzes etc be exported to your own OppiaServer, you can add a new connection (from link in the block)
I need to work on this to make it more obvious what the Moodle user needs to do, or at least specify a default server, so these errors don't confuse users.
Thanks for flagging this up,
Cheers,
Alex