Some ideas ?
Connect to dl.bintray.com:443 [dl.bintray.com/220.127.116.11] failed: connect timed out]
says it all, doesn’t it? Check your network/firewall/proxy settings to make sure that openHAB can download the add-ons.
Yes it does. Changing the firewall settings is no option since my openHAB2 is running on a remote system. I installed a local version, added all bindings I needed and pushed it to the remote. Now its working as expected. Thanks @Kai