Magento 2.3.1 upgrade Errors

Question

I am trying to upgrade magento2.2.3 CE to 2.3.1CE on staging server (magemojo)

After upgraded getting the below errors. Please can anyone face these below issues suggest me how to fix?

1.Unable to unserialize value. Error: Syntax error

fallowed this link https://magecomp.com/blog/solved-unable-to-unserialize-value-magento-2-2/

2.Type Error occurred when creating object: Magento\Framework\Interception\Config\Config

3.PHP 7.1.27 currently using.

Answer 1

Please upgrade your php version to 7.1.X or above and install all the required below php packages:

• PDO/MySQL
• mbstring
• mcrypt
• mhash
• simplexml
• curl
• gd2, ImageMagick 6.3.7 (or later) or both
• soap

Answer 2

Type Error occurred when creating object: Magento\Framework\Interception\Config\Config

I ran into this error when deploying code updates to a Magento 2.3.2 site using Capistrano. I solved the problem by flushing the Redis cache (as Saphal Jha suggested):

cat app/etc/env.php

Example output from that command:

<?php
return [
    'session' => [
        'save' => 'redis',
        'redis' => [
            'host' => '/var/run/redis-multi-aa45d208.redis/redis.sock',
            'port' => '6379',
            …
        ]
    ],
    'cache' => [
        'frontend' => [
            'default' => [
                'backend' => 'Cm_Cache_Backend_Redis',
                'backend_options' => [
                    'server' => '/var/run/redis-multi-aa45d208.redis/redis.sock',
                    'database' => '0',
                    'port' => '6379'
                ],
                'id_prefix' => '7ef_'
            ],
            'page_cache' => [
                'backend' => 'Cm_Cache_Backend_Redis',
                'backend_options' => [
                    'server' => '/var/run/redis-multi-aa45d208.redis/redis.sock',
                    'database' => '2',
                    'port' => '6379',
                    'compress_data' => '0'
                ],
                'id_prefix' => '7ef_'
            ]
        ]
    ],
];

After identifying the Redis information, I flushed the Redis cache, which solved my issue:

redis-cli -s /var/run/redis-multi-aa45d208.redis/redis.sock flushall