Cleartext HTTP traffic to myserver.com not permitted on Android N preview

Yesterday I got a new upgrade for the Android N preview. Ever since I upgraded, I cannot start my app anymore.

java.io.IOException: Cleartext HTTP traffic to myserver.com not permitted

I have tried to set the usesCleartextTraffic to true in the manifest or to add a network_security_config.xml

<?xml version="1.0" encoding="utf-8"?><network-security-config><domain-config cleartextTrafficPermitted="true"><domain includeSubdomains="true">myserver.com</domain></domain-config></network-security-config>

Neither did work. Any ideas about what is going on there?

When I try to define networkSecurityConfig in the manifest, I get a compile error

Error:(35) No resource identifier found for attribute 'networkSecurityConfig' in package 'android'

Not really sure why. The file is there and everything looks good.

Found this suggestion in the Android issue tracker from Google. They suggest to move the network_security_config definition to the meta-data. I still get the same exception though.