If I add a plugin to the config.xml and upload my project, the config appears to be malformed.
For me it was nothing but a closing tag for plugin:
Incorrect:
<plugin name="cordova-plugin-whitelist" >
Correct:
<plugin name="cordova-plugin-whitelist" />
Some time issue came for android Build use of this lines
<widget id="com.example.app" version="1.0.0" xmlns="http://www.w3.org/ns/widgets" xmlns:gap="http://cordova.apache.org/ns/1.0" >
for that we need to add this line xmlns:android = "http://schemas.android.com/apk/res/android" also of code Prevent the Malformed in Config.xml
complete : <widget id="com.example.app" version="1.0.0" xmlns="http://www.w3.org/ns/widgets" xmlns:gap="http://cordova.apache.org/ns/1.0" xmlns:android = "http://schemas.android.com/apk/res/android">
I think the issue may be that you are using
<widget id="com.example.app" version="0.0.1" xmlns="http://www.w3.org/ns/widgets" xmlns:cdv="http://cordova.apache.org/ns/1.0" >
(because you created the project using cordova and not phonegap)
which is correct for a cordova project but maybe not for a phonegap build project (and not allow plugins).
try with
<widget id="com.example.app" version="1.0.0" xmlns="http://www.w3.org/ns/widgets" xmlns:gap="http://phonegap.com/ns/1.0">
Important part is xmlns:gap="http://phonegap.com/ns/1.0" instead of xmlns:cdv="http://cordova.apache.org/ns/1.0"