Cannot scale up

I just finished drawing and want to scale it by x4 and I cannot due to the following issue/message : sketch cannot be scaled because it cannot respect contraints. For what I checked there is no contraints left like hor/vert how can I solve my issue?

Hi Michel,
Make sure there are no dimension constraints in your sketch (size of slots etc.) In sketch mode, open the constraints settings and turn both options on. Any dimensions you see that are locked need to be unlocked.