Copiar Caminho da Máscara no Caminho de uma nova Camada de Forma não está funcionando

Try this.

1. Set and then Copy or Cut a single keyframe for your mask.
2. Select the Pen tool and choose a stroke and fill for the shape. 
3. Make sure that no other layers have been selected, then click anywhere in the Comp panel to start a new Shape Layer using the pen tool
4. When the first point has been added to the new shape layer, Paste (Ctrl/Cmnd + v)

This should give you a new shape with the fill and stroke set for the pen tool. 

You may already have successfully created a new shape layer path, but there may not be a Fill or a Stroke assigned to that path. Try spinning down all of the properties in the shape layer and look for the path, a Fill, and a Stroke. If you don't find any, you can use the Add menu to add them. 

Also make sure that the background of your composition is not also white. Change it or click on the chessboard to see if the mask alpha is running or not. Also, try changing the mask application mode to "Add", in your capture you have it set to "Difference", change it to test.

Hey Thay Reis,

Could you let me know what you are trying to create by copying the mask path to another shape layer? If you want to use the mask path as a stroke, you must copy it to a new Path and add a stroke by clicking on the arrow next to "Add" to see it. If this is not what you were looking for, please share a screen recording of the issue so we can better understand what problem you are experiencing.

Regards,
Ishan