Hi Filipe,
This happens because ElasticSearch is not enabled.
This issue has to do with ElasticSearch. Check if Elasticsearch is installed and if it is, enable connection in sysconfig files (/etc/sysconfig/archivematica-dashboard). Example:
ARCHIVEMATICA_DASHBOARD_DASHBOARD_ELASTICSEARCH_SERVER=localhost:9200
ARCHIVEMATICA_DASHBOARD_DASHBOARD_SEARCH_ENABLED=true
Murilo Souza
Advisor
Public Archives of the State of São Paulo