Why can't I select and deselect the Groups in my Motion project?

You probably have some layer Solo'd... probably "pexels-pietro...". You can control click the layer and uncheck Solo from the popup (or from the Object menu). If you know the layer is soloed, you can Option Click the checkbox to toggle the state.

Once a layer (or group) is soloed, you can't change the visibility states of any of the others.

It is sometimes easy to accidentally solo a layer (or group) and if you can't tell which one is soloed, you have to go through the entire list to find it.

I think there's a way to clear any soloed item without knowing which one, but for the life of me I can't remember it right now.

fox_m wrote:

You probably have some layer Solo'd... probably "pexels-pietro...". You can control click the layer and uncheck Solo from the popup (or from the Object menu). If you know the layer is soloed, you can Option Click the checkbox to toggle the state.

Once a layer (or group) is soloed, you can't change the visibility states of any of the others.

It is sometimes easy to accidentally solo a layer (or group) and if you can't tell which one is soloed, you have to go through the entire list to find it.

I think there's a way to clear any soloed item without knowing which one, but for the life of me I can't remember it right now.

Great advice, as usual, Fox!

To unsolo everything, one can select all layers and do Object->Unsolo->Videon and Audio.

You Can select them, in fact Group 1 IS selected in the image you posted.

Maybe your question refers to the - sign. That usually means that some of the items in it are active, and some are not.