Unable to Clone Stamp after creating 3D spherical panorama

[rsupernature]

I'm trying to use clone stamp to remove the tripod from my 360 photo and followed several tutorials, where they first create a new spherical panorama from the selected layer, then set the camera position and use clone stamp tool. However, when I try that, Photoshop throws the error "Could not edit the texture(s) directly. Please open the texture(s) and choose an editable target layer to proceed".

Why is the layer in my photo not editable?

If I create an additional Layer1 and copy the Layer0 into it, then I can edit (use clone stamp) in that layer1, but then get the same error when attempting to merge down.

[Abambo]

See here: https://helpx.adobe.com/photoshop/using/3d-texture-editing.html.

You mapped your picture on a 3d body. This makes a texture from a picture.

[rsupernature]

Thanks, but since several tutorials I've seen don't need to do that, I suspect there is something that can be configured when a 360photo is imported that means you can use editing tools directly on the original layer. 
one of the tutorials included a step to rasterise the image before using editing tools like clone stamp, but again this was only one and all the others don't do that. 

[rsupernature]

I think the problem was that I opened the 360 photo as an embedded smart object

[jpbees]

How did you solve this issue? I cannot figure it out. Nor do I understand the comment about opening the 360 as an embedded smart object. How am I doing that? How do I not do that? I'm working with tiffs here. Thanks for any help!