Magento 2.3.4 error while upgrading to Magento 2.4.0

Question

I upgrade to version 2.3.4 to version 2.4.0 but I have an error. I have searched on google but it is not working.

Problem 1

- magento/magento2-functional-testing-framework 2.4.5 requires php 7.0.2||7.0.4||~7.0.6||~7.1.0||~7.2.0||~7.3.0 -> your PHP version (7.4.9) does not satisfy that requirement.
- magento/magento2-functional-testing-framework 2.4.5 requires php 7.0.2||7.0.4||~7.0.6||~7.1.0||~7.2.0||~7.3.0 -> your PHP version (7.4.9) does not satisfy that requirement.
- Installation request for magento/magento2-functional-testing-framework 2.4.5 -> satisfiable by magento/magento2-functional-testing-framework[2.4.5].

Answer 1

Your generally problem is PHP versions issues.Your PHP version is 7.4.9.But Magento 2.4 PHP version requirements is 7.3.

So,Your Problem is you downgrade your PHP Version and try Again.

How to downgrade PHP Version For XAMPP:-

https://stackoverflow.com/a/51906677/11908692

How to downgrade PHP Version For ubuntu :-

https://webdock.io/en/docs/perfect-server-stacks/upgrading-or-downgrading-php-versions

THANKS.

Answer 2

I think that given that you're upgrading from Magento 2.3.4 (which requirement is PHP 7.3) to Magento 2.4 (which requirement is PHP 7.4), you could try to avoid system checks.

So try to run composer update with the param:

composer update --ignore-platform-reqs

This will avoid PHP version checks.

Answer 3

Because your current version is higher than 7.3.0, your php version is 7.4.9. So you need downgrade to 7.3.0 and then retry again.