A lot of people are experiencing that.
I just ran into the same problem. It seems it has to do with a new security policy in new versions of Cordova.
Here’s how I solved it:
I installed Cordova’s whitelist plugin :
cordova plugin add cordova-plugin-whitelist
Then, add your content policy in your index.html
as a meta tag (using your own host or ‘*’ for accepting all requests) :
<meta http-equiv="Content-Security-Policy" content="default-src 'self' yourhost.com ws://localhost:35729 data: gap: https://ssl.gstatic.com; style-src 'self' 'unsafe-inline'; media-src *;script-src 'self' localhost:35729 'unsafe-eval' 'unsafe-inline';">
Best Solution
Had a same problem, nothing helped, then i just removed the whitelist plugin:
cordova plugin remove cordova-plugin-whitelist
then re-installed it
cordova plugin add cordova-plugin-whitelist
then it worked