Cannot "proceed to checkout" on certain product

Question

When I add a particular product to my cart, I cannot proceed to checkout.

When I click "Proceed to checkout" on the shopping cart page, it just redirects me back to the same page.

I do not have any JS errors, nor do I have any errors in my error logs that come up when this happens.

The product is just like many others I have on the site, it's in stock.

I've cleared my caches, reindexed, etc, but nothings seems to work.

Any ideas?

Answer 1

This ended up being an issue with a custom option dependency being set to required, when it didn't need to be. It passed the Javascript validation to add it to the cart, but failed on the checkout page.