Problem with 3d Print , Layers does not stick together

[stoque 0]

hello , i m new to 3d printing

i have a ultimaker 2.0

while printing the layers are not sticking together properly ( See pictures)

What could that be ? i made quite a few prints with this machine but this problem is new

thanks a lot

fabi

[JohnFox 25]

I think the the bed/nozzle gap is too large, it's not having chance to push the filament onto the bed.