@David1611
There are few different reasons for mobione failing to download the app binary file, e.g., network timeout…
Suggestions:
1) try building the app again, perhaps the apk download will complete with another try
2) manually download the apk
– use the email notification to receive a link to a web installer
– from the email notification launch the link in a Chrome browser instance. This will load the web installer for your app
– click the install button to start downloading
— the apk file will be downloaded with a cryptic file name such as x8adsf8dfnadf.
– rename the cryptic file to <yourappname>.apk – do not use spaces or special chars in the file name, keep it simple
– tested this process and used GapDebug to install the app on my device and verify it runs. Note the app will install with the name you defined in the build wizard, not the filename you give it. See 1 min video installing app using GapDebug (free) https://www.genuitec.com/gapdebug-drop-apps/