By default, Windows services run under the “Local System Account” (in versions 2020 R2 SP1 and later under “NT SERVICE\RTM Reporting System Runtime Manager“). That account has limited rights, so any resource that requires certain privileges (access to network shares, networked printers, SQL Server logins, etc.) will likely not be accessible. So, in Windows Services, open the “RTM Reporting System Runtime Manager” service, click on the “Log On” tab, and change Log on as: to a specific Windows account that has the necessary privileges – this is now the account under which Dream Report will run. Also make sure that this account does not expire, or does not have an expiring password.
During Dream Report upgrade, the service will be set up with the default account, so please reconfigure it to use Windows account if necessary.