| Product(s): | WaterCAD, WaterGEMS, SewerCAD, SewerGEMS, StormCAD, CivilStorm, HAMMER |
| Version(s): | Up to 26.00.00.532 |
| Area: | Installation |
Problem
After upgrading AutoCAD 2026 to the 2026.1.2 version (August 5th, 2026 update, 25.1.179.0 or higher) or upgrading Civil 3D 2026 to the 2026.2.2 version (August 5th, 2026, 13.8.1809.0 or higher), integration with OpenFlows products stopped working and the following error messages appear when trying to open the "...for AutoCAD" shortcut:
"BinaryFormatter serialization and deserialization have been removed..."
"Object reference not set to an instance of an object."
"Error Message: Unspecified error."
Background
This issue is caused by a breaking change made by Autodesk in this minor update, related to to .NET architecture. (for all types of AutoCAD, including Civil 3D).
This update upgraded the architecture from .NET 8 to .NET 10, which breaks integration with OpenFlows products because the OpenFlows components rely on the original .NET 8 used when AutoCAD 2026 was originally released. This is not a change that Bentley could have foreseen or tested for compliance because the update was not available at the time our most recent versions were released (26.00.00.532). Bentley always fully tests our products with the most current releases of AutoCAD, and this update was not available at the time, so we could not have made our integration compatible. Furthermore, historically all minor updates and patches to a major release (year number) did not break our integration, so there has been no need for Bentley to closely monitor for AutoCAD updates and patches (until another new OpenFlows version is released).
With that said, our development team is currently working on making the necessary changes on the OpenFlows side to support integration with these new .NET 10-based AutoCAD 2026 update versions (reference #2125445). This may take the form of a patch, or an enhancement to the next releases (starting with 26.00.01.XXX, expected to be available in October, 2026).
Solution
Because Autodesk broke integration in this way, the current solutions are:
- Roll back the 2026 update (which may require uninstalling AutoCAD 2026 and reinstalling)
- Use an earlier, compatible version such as AutoCAD 2025. If you need to install it, run the OpenFlows integrator shortcut (see Start menu - "Integrate WaterGEMS with...") after installing AutoCAD 2025, to create the "...for AutoCAD 2025" shortcuts.
- Use the Standalone version of the OpenFlows product. See this article, which explains the many CAD-related features available in the Standalone version, which my satisfy your needs.
- Once it is available from Bentley, update your OpenFlows product to a new version or apply a patch if it becomes available. See: How to receive alerts on new version availability. You can also submit a Case to Technical Support via the Support Portal, to get an update on this issue (patch or estimated version release date).
Note: Autodesk also plans to release a similar update to AutoCAD 2025 in September of 2026, which we also plan to address.
See Also
AutoCAD Integration Troubleshooting
CAD Functionality in Standalone as an Alternative to AutoCAD or MicroStation Integration