happy new year!
I've just made an so called minor upgrade after it was finished the Notification window opened and I clicked the button 'Check for Availabel updates', even I Know I've just upgrades already.
Any way, I got the error message error/core plugin/err response curl and after turning debugging on I got the following output as well:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
Error code: err_response_curl
- line 1187 of /lib/pluginlib.php: available_update_checker_exception thrown
- line 1073 of /lib/pluginlib.php: call to available_update_checker->get_response()
- line 475 of /admin/index.php: call to available_update_checker->fetch()