CiviVolunteer Not Working After CiviCRM 5.5.2 Upgrade
Matt,

Can you perform CiviCRM cleanup cache? This usually happens when menu is not registered. You can do this by navigating to CiviCRM >> Administer >> System Settings >> Cleanup caches and reset paths and then click on cleanup cache. Or you can just hit the url with civicrm/menu/rebuild&amp;reset=1

HTH

Pradeep