Unable to edit existing materials and new materials won't change dimensions on MacOS

I’ve attempted to edit existing materials by using the colors drop-down menu and right-clicking the material, but all of the options are greyed out.

I tried adding new materials, and they allow me to edit them using the method I just stated, but none of the changes seem to apply. I tried changing the dimensions to increase the size of one of the materials, but it stayed the same.

Are there any solutions for these issues?

You can only edit In Model materials. Add the material to your model file, click on the house icon or select Colors in Model and then you can edit the material.

Thank you! I’m still relatively new to sketch up and haven’t worked with materials very much.