Drupal 9 (seems to be) shipped with symfony/dom-crawler version 4 while this module is requiring version 3, preventing a full upgrade.
Try to upgrade to Drupal 9 with this module installed.
Not sure at all that this is the best/correct solution - but it resolves the problem as seems to work correctly.
Review if this is the correct solution.
None.
Should be none.
Should be none.
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
