Yes, the installer size is correct (592KB).
MDG DOORS v3 requires DOORS 9.6.1 or higher. It's not supported for connection to DOORS 8.3.
Do you have more than one version of DOORS installed on your system? This has been known to cause issues.
If needing further assistance, can you please send an email to support@sparxsystems.com with the steps you are following with MDG DOORS v3 and DOORS 9.7? Include details such as your EA version, MDG version, DOORS version(s), Operating System etc. Also include screenshots where possible.