Unexpected token < in first line of HTML

Your page references a Javascript file at /Client/public/core.js.

This file probably can't be found, producing either the website's frontpage or an HTML error page instead. This is a pretty common issue for eg. websites running on an Apache server where paths are redirected by default to index.php.

If that's the case, make sure you replace /Client/public/core.js in your script tag <script type="text/javascript" src="/Client/public/core.js"></script> with the correct file path or put the missing file core.js at location /Client/public/ to fix your error!

If you do already find a file named core.js at /Client/public/ and the browser still produces a HTML page instead, check the permissions for folder and file. Either of these might be lacking the proper permissions.

In my case I got this error because of a line

<script src="#"></script> 

Chrome tried to interpret the current HTML file then as javascript.