Before posting here I would strongly advice to search and look in the forum for existing answers as most of the problems many have allready been aswered by other users.
In most cases the problems and errors after an upgrade is due to Third Party Extensions and Themes that need to be updated with solutions from the developers direclty.
Any suggestion / solutions to problems should be posted as a answer here in the forum, and not linked to github for quick solutions since Magento can not provide and guarantee the safety for other developers code that is not provided by Magento.
