QuickBooks data file connectivity issues, Are you running into issues with getting your Quickbooks 2021 Database Manager service running? More up to date form of Quickbooks use arbitrary ports that at some point conflict with the ports reserved for the DNS Server service. Your QuickBooks desktop application has not been updated to the newest release from Intuit.The database server manager required to use QB in multi-user mode isn't installed or updated properly. A firewall is obstructing certain services thanks to limited permission to access certain files from the server. Lets know how to fix Quickbooks 2021 Database Server Not Running issue. Source: https://www.repaircontact.com/quickbooks-2021-database-server-not-running.php