I get this after updating from 2.1 to 2.2
1 exception(s):
Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'block', attribute 'class': [facet 'pattern'] The value '\\Magento\Framework\View\Element\Template' is not accepted by the pattern '[A-Z][_a-zA-Z\d]*(\\[A-Z][_a-zA-Z\d]*)*'.
Line: 687
Element 'block', attribute 'class': '\\Magento\Framework\View\Element\Template' is not a valid value of the atomic type 'blockClassType'.
Line: 687
Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'block', attribute 'class': [facet 'pattern'] The value '\\Magento\Framework\View\Element\Template' is not accepted by the pattern '[A-Z][_a-zA-Z\d]*(\\[A-Z][_a-zA-Z\d]*)*'.
Line: 687
Element 'block', attribute 'class': '\\Magento\Framework\View\Element\Template' is not a valid value of the atomic type 'blockClassType'.
Line: 687
I already read topic on github with same problem but idk what I supposed to do to fix this.
Now I fixed broken class in one of files in app/code And get the "Attribute layout redefined" with checkout_index_index.xml I deleted this file and completely get this:
Element 'move', attribute 'name': The attribute 'name' is not allowed.
Line: 687
Element 'remove': This element is not expected. Expected is one of ( block, container, referenceBlock, referenceContainer, uiComponent ).
Line: 723
Also code of my chekout_index_index.xml because i delete, not fix it
<?xml version="1.0"?>
<page layout="empty" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="checkout" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceContainer name="page.messages" remove="true" />
<move element="logo" destination="checkout.header.wrapper" />
</body>
</page>