Refused to get unsafe header "Location" Only in Safari
<p>I am currently debugging my website. It seems to work perfectly fine in Safari except for the following error being thrown in the background (see img1 and img2). However, these errors are not thrown in Chrome and the Vaadin comboboxes fail to load as well. <strong>I am wondering what the error means:</strong></p>

<blockquote>
  <p>Refused to get unsafe header "Location"</p>
</blockquote>

<p><strong>Img1</strong>
<a href="https://i.stack.imgur.com/KWSLH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KWSLH.png" alt="Img1"></a>
<strong>Img2</strong>
<a href="https://i.stack.imgur.com/qzr3e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qzr3e.png" alt="Img2"></a></p>

<p>I think it will be a good hint as to why Safari works, but Chrome does not. It appears to me that Safari works because it has refused to fetch something from Vaadin, and because Chrome is successful then a flaw in my code is able to execute.</p>

<p>Edit:
These are the errors thrown in Chrome (img3). Note that the comboboxes do not display (they do display in Safari).</p>

<p><strong>Img3</strong>
<a href="https://i.stack.imgur.com/wmB8K.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wmB8K.png" alt="img3"></a></p>