1. Ok, so I purchased the theme from Envato theme forest. 
2. I downloaded and installed the Envato update plugin
3. I updated the Soledad demo installer plugin
4. deactivated every 'beta' Elementor plugin except their flexbox container plugin, and this worked. I can now edit using elementor.

Then I reactivated the following 'beta elementor features one by one 

1. Grid container.  This worked.  I was still able to edit pages
2. Editor Top Bar. This worked.  I was still able to edit pages
3. Nested Elements.  This worked.  I was still able to edit pages
4. Global Style Guide. THIS DID NOT WORK.  THIS PLUGIN CRASHED THE EDITOR
5. Menu. This worked.  I was still able to edit pages

When I purchased the soledad theme, the one requirement I had  and checked on was compatibility with Elementor, so I could use elementor to edit my pages.  

Elementor does not work.  I get an error message.  I have tried all the Elementor remedies including deactivating every plugin and turning them on, one by one.  

Nothing.  Elementor seems not to work at all with the Soledad theme!

Please kindly explain how to fix this, or refund my purchase order.

Thanks