Question:

Whenever I open a file with a referenced DWG, ORD will crash. How do I stop this?

Answer:

Make sure everyone has the correct object enablers installed. You will need to find out what version of Civil3D was used for the .dwg files and install the appropriate versions.
https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Download-Object-Enablers.html
If you have the correct object enablers installed and you still run into issues, add an underscore ( _ ) at the end of each object enabler's folder name (i.e. Civil 3D 2021 Object Enabler changes to Civil 3D 2021 Object Enabler_)
If a custom location is being used for the MS_TRANSEED in the workspace, check to make sure that the path for the MS_TRANSEED is being found by the DGN file.
If the previous suggestions don't work, move the transeed.dgn to a different folder. MS_TRANSEED points to the following folder path by default:
C:\Program Files\Bentley\OpenRoads Designer CE XX.XX\OpenRoadsDesigner\Default\Seed

IMPORTANT: Option #4 is a temporary workaround. The transeed.dgn is important to have when working with .dwg files, as it fills in information such as the Global Origin, Working Units, and colors that are not stored in the native AutoCAD file. DWG references won't load when the transeed.dgn is moved, so it is best to move it back to the original folder when possible.