The release of Autodesk Civil 3D 2020 has brought a change to the Survey Database format. Survey Databases are now saved in SQLite format instead of Microsoft SQL Server Compact (SQL CE) format. To use existing survey databases with Civil 3D 2020, they need to be converted to SQLite.

In past releases, a survey database could be migrated to a newer version inside of Civil 3D. This is no longer the case in Civil 3D 2020. To migrate an older survey database to use in Civil 3D 2020, you must use a migration tool. If you try to use an older database, you will be prompted to download and install the Autodesk Civil 3D Survey Database Migration Utility.

The Autodesk Civil 3D Survey Database Migration Utility is also available as a separate download from the link below.

https://knowledge.autodesk.com/support/civil-3d/downloads/caas/downloads/content/survey-database-and-migration-tool-for-autodesk-civil-3d.html

Make sure to note, once a survey database is migrated to SQLite format, it is not compatible with releases earlier than Civil 3D 2020.