<div>Data Migration Tool – There are no commands defined in the “migrate” namespace.</div>

I am trying to migrate data from CE 1.9.4.1 to CE 2.3.5-p1.

I installed the Data Migration Tool as per https://devdocs.magento.com/guides/v2.3/migration/migration-migrate.html, and configured it to run the migration in a separate module. However, when I try to start with settings I get ‘There are no commands defined in the “migrate” namespace.’

composer require magento/data-migration-tool:2.3.5

./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Package container-interop/container-interop is abandoned, you should avoid using it. Use psr/container instead.
Package phpunit/phpunit-mock-objects is abandoned, you should avoid using it. No replacement was suggested.
Generating autoload files
PHP CodeSniffer Config installed_paths set to ../../codeception,../../magento/magento-coding-standard,../../phpcompatibility/php-compatibility

php bin/magento migrate:settings -r /<magento_dir>/app/code/etc/opensource-to-opensource/1.9.4.1/config.xml

  There are no commands defined in the "migrate" namespace.

I have run composer to install the Data Migration Tool several times and I cannot get past this error. When I run php bin/magento I get

In ClassReader.php line 43:

  Class MigrationAppModeStepListFactory does not exist

In ClassReader.php line 36:

  Class MigrationAppModeStepListFactory does not exist

Any help would be appreciated!