This is caused by the Microsoft Access Database Engine (ADE), which is a separate component installed in Windows and is used to read the InRoads drainage SDB file.

 

If your Inroads SBD file is very old and you are using a recent version of the OpenFlows or OpenRoads application, you may have encountered a limitation with the Access Database Engine version 2016. Your Inroads database may be too old to be opened by this version and you may need to use 2010 instead of 2016.

 

You can also try to repair/upgrade the file using a free utility such as MDB Viewer Plus (external link) You can download it from that website and run it (it doesn't have to be installed). Open the sdb file in the utility and go to Tools -> Repair and Compact. Save the file as Test_repaired.sdb. Try to import the repaired file. It may display several user notifications, but it should open successfully.

 

Note that some very old .SDB files are not even supported by Microsoft and cannot be opened in recent versions of Microsoft Access itself.

 

Also, ensure that the correct version of ADE is installed, per the articles below. If using the 64-bit OpenRoads Designer or StormCAD for example, ensure ADE 2016 or 2010 64-bit is installed.