Your first column doesn't have a closing tag.
I have the same problem, but I don't understand what do you mean "Your first column doesn't have a closing tag"
An example of a column without a closing tag:
<div class="col-md-4"> <div class="thumbnail"> the image link </div> <!-- closes thumbnail --> <div class="thumbnail"> the image link </div> <!-- closes thumbnail -->
You can see that there is no closing tag for the col-md-4 div.
im getting the same error messages, but I cant figure out where I messed up
You might be missing a tag or have an extra tag, or you could have placed your code in an unexpected place, or you could just have a typing mistake. Those are all possibilities. This is a big enough project that it is unlikely that anyone will be able to just guess where your error message is coming from.
If you want help you are going to have to post your code, make sure you use the
</> button on the editor's toolbar so that your code will show as text and not be rendered as HTML.
It is a bit hard to see, because you haven't used an indenting, but your second thumbnail and your first column both are missing their closing tags.