I have a totally default installation using the Luma theme. When you go to the cart page there is no checkout button. Only a link for "Check out with multiple addresses". I have turned off single page checkout but I don't see why that would make a difference. Any ideas?
Just had the same issue, was a combination of these 2 things:
- The default Tax Destination country (under Sales -> Tax) was set to USA while that was not one of the allowed countries under General -> General
- Disabled one-page checkout
After making the default tax country the same as my default country (under general -> general) and enabling one-page checkout the "Proceed to Checkout" button appeared.