Anim Montage is not working?

Hi,
I was following an excellent guide from Ryan Laley but came to a halt where he plays an anim montage. For him it worked, for me it did not.

I made some other projects with anim montages and never had a problem so I figured I just set up a simple play montage test so I took the run animation and made a montage of it to play in the default slot.

I hoop up the defaultslot in my very simple animBP (Idle animation → defaultslot → Output Pose )

In my charBP i put G as action input to print string (G key is pressed - for debug) and then Play montage where I selected the run anim montage (played in defaultslot) and drag my mesh to the pin in skeletal mesh component.

The only thing that happens when i press G is the debug text G key is pressed to screen but it wont play the anim montage.

I started a new 3d project and did the same setup and there it works as intended, when i press G the char do the run animation.

Any Ideas why its not working in the tutorial project when it seems like its set up correct (I doublechecked like 5 times now).

Anyone else that had this problem and know how to solve it?