I have Moodle 2.8.3 (Build: 20150202) branch 28 installed. This is an upgraded version of Moodle, we did start with 2.1 back then.
Webservices is turned on, mobile service is turned on. The whole site is running with HTTPS.
When I try go log in with the mobile app, it always tells me that required parameter username is missing.
I already found other discussions about this topic, but none of the provided solutions did solve my problem. Does anybody have a hint where I could start look at to be able to get to the bottom of this?