Error in the panel when sorting pages on root

Maybe it’s just me, but I get errors when in the panel in the root and click “Pages” to sort them. Here are a few of them.

Any ideas? Kirby 2.3.

Notice: Undefined property: Kirby\Panel\Collections\Children::$data in C:\wamp\www\vf\kirby\toolkit\lib\collection.php on line 512

Warning: array_change_key_case() expects parameter 1 to be array, null given in C:\wamp\www\vf\kirby\toolkit\lib\collection.php on line 512

Notice: Indirect modification of overloaded property Kirby\Panel\Collections\Children::$data has no effect in C:\wamp\www\vf\kirby\toolkit\lib\i.php on line 47

Fatal error: Call to a member function uid() on a non-object in C:\wamp\www\vf\panel\app\snippets\subpages\subpage.php on line 1 Call Stack #TimeMemoryFunctionLocation 10.0007253648{main}( )…\index.php:0 20.09406271712Kirby\Panel->launch( )…\index.php:51 30.33237138216Response->__toString( )…\index.php:404 40.33277179800Kirby\Panel\View->__toString( )…\index.php:139 50.33277179928Kirby\Panel\View->render( )…\view.php:34 60.33297180040Tpl::load( )…\view.php:29 70.33327207656require( ‘C:\wamp\www\vf\panel\app\layouts\app.php’ )…\tpl.php:22 80.33597210824Kirby\Panel\View->__toString( )…\tpl.php:27 90.33597210952Kirby\Panel\View->render( )…\view.php:34 100.33617211072Tpl::load( )…\view.php:29 110.33657264112require( ‘C:\wamp\www\vf\panel\app\views\subpages\index.php’ )…\tpl.php:22 120.41387308488Kirby\Panel\View->__toString( )…\tpl.php:43 130.41387308488Kirby\Panel\View->render( )…\view.php:34 140.41407308608Tpl::load( )…\view.php:29 150.41467336696require( ‘C:\wamp\www\vf\panel\app\snippets\subpages\subpage.php’ )…\tpl.php:22

Is that a fresh install or do you have any panel extensions installed?

Edit: If you have any extensions installed, try to remove them and re-add them one by one to find what might be causing these messages.

I removed all the plugins and the problem remains. (I also logged out and in again)

Maybe I should start from a fresh install, just copy the stuff (content, snippets ect) bit by bit.