When setting up a new head, the dialog that displays the head symbols to be selected appears, is empty, and then drawing crashes,

When attempting to open HydraCALC Sizer, you get this error;

Error:260:0:0

"Well this is new, not sure what's happening with your hardware lock, please get a current 'fix file' from Hydratec"

Error occurs when using some commands.

Autodesk has just released AutoCAD 2026.1.2 - and it breaks HydraCAD. It includes a major programming change by Autodesk that will require a lot of work and a large update by us. That update is being worked on right now, along with a version of HydraCAD for AutoCAD 2027. Both are now affected by essentially the same programming change.

BinaryFormatter serialization and deserialization are disabled within this application. See  https://aka.ms/binaryformatter for more information.

When viewing a plot, hydraulic reference points in the HYD2 layer have thick text.  Editing lineweights for the layer does not make a difference.

Error occurs when tying to select any option in the Hangers button

Using negative floor elevations and drop windows with specified lengths, drops give a warning that takeout was greater than it's length, when going to 3D.

Error Finding Hanger Information when generating 3D Hangers

Revit could not complete the external command... Family symbol is not valid for this instance

When trying to place a hanger you get this warning.

"There are identical instances in the same place. This will result in double counting in schedules."

HydraCAD for AutoCAD drawing models imported into AutoCAD or Navis do not show Properties for our custom objects: HydraPIPEs, HydraHEADs and HydraFittings on machines without our software.

Launching AutoCAD causes a hard system crash as it loads some HydraCAD plugins, the last one seen is HCADMainBase.arx. The machine crashes every time — it does not reach the AutoCAD interface. When HydraCAD is uninstalled, AutoCAD launches and runs normally with no crashes.

Opening AutoCAD/Revit/Navis gives Device limit reached message after opening a drawing or model.

Opening AutoCAD/Revit/Navis gives Device limit reached message after opening a drawing or model.

When placing clevis hangers or adjustable ring hangers on a 10-inch pipe drawing in Revit, the hangers render incorrectly with missing 5/8 rods.

When trying to add reference points, none are added and this error shows:

After inserting a valve, it does not appear in the 3D view. There is blank space where the valves should be. 

All building dimensions are inserted into an different layer than the current one.

In Navisworks 2024.2 to Navisworks 2025.3 (possibly a sub-version earlier or later), Properties for appended HydraCAD persistent models do not appear, and a Proxy Object notice is given.

When opening Hydracad you get the following error:

Unhandled exception has occurred in a component in your

application. If you click Continue, the application will ignore this error

and attempt to continue.

Retrieving the COM class factory for component with CLSID

{44D62FAE-67A7-4131-BF38-489CDFE44738} failed due to the

following error: 80070005 Access is denied. (Exception from

HRESULT: 0x80070005 (E_ACCESSDENIED)).

When opening Hydracad you get the following error:

Unhandled exception has occurred in a component in your

application. If you click Continue, the application will ignore

this error and attempt to continue.

Retrieving the COM class factory for component with

CLSID {44D62FAE-67A7-4131-BF38-489CDFE44738}

failed due to the following error: 80070424 The specified

service does not exist as an installed service. (Exception

from HRESULT: 0x80070424).