title: Unable to create new Product in Magento 2.3.x (Blank Page)
body: <p>I have recently installed Magento 2.3.5-p1/2.3.4 with sample data (different versions to solve this problem) and everything seems to work fine in frontend or admin panel. However, if I try to create new customer, or new product, or view current pages I have, or themes option in admin panel I get a blank page.</p>
  <p><strong>1. Admin &gt; Content &gt; Pages</strong></p>
  <p><a href="https://i.stack.imgur.com/rxZZr.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rxZZr.png" alt="enter image description here" /></a></p>
  <p>.</p>
  <p><strong>2. Admin &gt; Catalog &gt; Products</strong></p>
  <p><a href="https://i.stack.imgur.com/pHAht.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pHAht.png" alt="enter image description here" /></a></p>
  <p><strong>3. Admin &gt; Catalog &gt; Categories</strong></p>
  <p><a href="https://i.stack.imgur.com/FvCY3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FvCY3.png" alt="enter image description here" /></a></p>
  <p>I don't have any errors in Nginx logs, however I see following type of errors in <code>system.log</code> which I believe should be ignored as thats what I found on the internet.</p>
  <blockquote>
  <p>[2020-07-13 05:52:54] main.INFO: Broken reference: the
  'product.reviews' element cannot be added as child to 'product_tabs',
  because the latter doesn't exist [] []</p>
  </blockquote>
  <p>I have already for help on several other forums but none was able to help, so I am finally posting here. I hope someone can guide me.</p>
  <p><strong>UPDATE:</strong></p>
  <p><strong>Affected page are:</strong></p>
  <pre><code>Admin &gt; Customers &gt; All Customers &gt; Add New Customer
  Admin &gt; Catalog &gt; Product
  Admin &gt; Catalog &gt; Categories
  
  Admin &gt; Content &gt; Themes
  Admin &gt; Content &gt; Configuration
  Admin &gt; Content &gt; Pages
  Admin &gt; Content &gt; Blocks
  </code></pre>
  <p><strong>Not Affected in these tabs:</strong></p>
  <pre><code>Admin &gt; Content &gt; Schedule
  Admin &gt; Content &gt; Widgets
  </code></pre>