As of version 7.15.0, the SMTP server account and Remote Approval incoming server account passwords are no longer encrypted in the web.config file.
Before upgrading an existing WorkflowGen server, you must manually reset the passwords in cleartext for the ApplicationSmtpPassword and RemoteApprovalIncomingServerPassword parameters in the web.config file. Alternately, you can use the convert-web-config-pwd.ps1 PowerShell script provided in \wfgen to decrypt and convert the passwords in the web.config .