migrate drupal 6 to drupal 8

Question

I have a website which is based on Drupal 6.26, and I want migrate to Drupal 8.1.7.

I have followed this guide: https://www.drupal.org/docs/8/upgrade/upgrade-using-drush

Although, I set up website successfully, and added 3 modules to "modules" folder.

But when I run this command: drush en migrate_upgrade migrate_tools migrate_plus -y

then an error has appeared:

PHP Fatal error:  Class Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher contains 1 abstract method and must therefore be declared abstract or
implement the remaining methods (Symfony\Component\EventDispatcher\EventDispatcherInterface::getListenerPriority)
in /public_html/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php on line 34
Drush command terminated abnormally due to an unrecoverable error.                                                                                                                   [error]
Error: Class Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher contains 1 abstract method and must therefore be declared abstract or implement
the remaining methods
(Symfony\Component\EventDispatcher\EventDispatcherInterface::getListenerPriority) in
/public_html/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php, line 34

Here is my environment's info:

・　Amazon Linux AMI 2016.03

・　PHP 7.0.10

・　PostgreSQL 9.2

・　Drupal 8.1.7

・　Drush 8.1.15

Can you please tell me what my problem is ?

Thanks !

Don't use Drupal 8.1.7, update that to Drupal 8.5.3 or whatever the latest version of Druapl is when you read this. — Frank Robert Anderson
I should be more clear, there have been major security advisories that have been fixed recently and no one should be using an un-patched version of Drupal. Also, Migrate wasn't stable in 8.1 and didn't get stable drupal core until 8.4 (I think). — Frank Robert Anderson

Frank Robert Anderson Frank Robert Anderson · Accepted Answer · 2018-05-25T14:40:31

Drupal 8.1.7 is very out of date. Please update to the latest version and try again. The Migration system wasn't stabilized till 8.4 or 8.5 so there are likely module incompatibilities to consider attempting to use newer contributed modules with an older version of Drupal.

Finally, there are open security vulnerabilities in Drupal 8.1.7 that will not be patched as it has been EOL. Each minor version of Drupal sees the previous minor version EOL and the current minor version as of this writing is 5.

migrate drupal 6 to drupal 8

1 Answers