Please share your App ID? (You seem to be posting this under an account that isn't on PhoneGap Build).
Sorry it was my fault. I use API for node.js to upload and download the app and I was saving it as .xap, and I should have saved it as .appx.
But if you don't mind I have another question now.
When I upload it to windows developer I get this errors:
Invalid package identity name
Invalid package family name
Invalid package publisher name
Where do I get those?
I added windows-identity-name, and now I only get this errors: Invalid package family name, Invalid package publisher name.
It seems to me that phonegap build builds the app for windows 10, but I want only for windows phone. So the one where I don't need to upload .pfx file for a key, but only enter publisher ID. I think this is the case because I can't select my windows phone key, but I can select my windows 10 key for the app.
So probably I'm not correctly setting config.xml.
Can I see anywhere what exactly must be in config.xml for phonegap build to build only for windows phone?
Ah ok you should use phonegap-version cli-5.4.1 or below to target WP8.
Yup, this is it. Everything works now. Thank you.