So, I added some code in Content Editor Web Part and code is started like this:
<script src="/<MyURL>/_layouts/15/SP.Runtime.js" type="text/javascript"></script>
<script src="/<MyURL>/_layouts/15/SP.js" type="text/javascript"></script>
<script src="/<MyURL>/SiteAssets/jquery-1.11.1.min.js" type="text/javascript"></script>
<script src="/<MyURL>/SiteAssets/knockout-3.0.0.js" type="text/javascript"></script>
<script src="/<MyURL>/SiteAssets/Script.js" type="text/javascript"></script>
For all these files I get a similar error for each in Chrome console:
GET http://MyURL/%3CSiteURL%3E/SiteAssets/knockout-3.0.0.js 400 (Bad Request)
...
I googled but the this error pops up so often for various situations that couldn't find answer for me and SharePoint. Any ideas?