Guess this is PHP7 problem
problem is with the code
'function' => $nextframe['function'],
$nextframe doesn't necessary contain function index, it can be for example
array (
'file' => '/vagrant/dev/admin/vendor/composer/ClassLoader.php',
'line' => 412,
'include_filename' => '/vagrant/dev/admin/app/SaaS/Admin/Models/User.php',
'args' =>
array (
),
)
Addressing undefined index leads to error posted in subject.