The calculation results shows a pressure requirement which does not show up in the Final Calculation printout

In the example below, 104.344 psi is nowhere in the Calculation Sheets of the printout.

When trying to sign-in to the Hydratec Portal after Confirming your account and entering a password, this error appears when trying to sign in. 

Despite clicking Confirm Account on the Invitation email, and setting up an account and password, an account was never actually created. 

Error 1723. There is a problem with this Windows

Installer package.  GetDriveLetter_Action can't find a .dll.

When trying to use the Hangers tool, and insert a Brace, it only allows for a single brace to be added.
It doesn't allow for continuous insertion as intended. 

Flex Pipes on Armovers list as TG pipes instead of TT 

If experiencing an issue with HydraCalc Sizer please contact support at:

(603) 434-0502
Support@HydraCAD.com

If experiencing an issue with your license please contact support at:

(603) 434-0502
Support@HydraCAD.com

If experiencing an issue with your physical hardware lock please contact support at:

(603) 434-0502
Support@HydraCAD.com

Pipe fittings in certain views were grayed out and could not be selected, making it impossible to edit or work with them.

Windows 11 Smart App Control is blocking HCADLoader.arx because Windows says it cannot confirm who published the file. HydraCAD then gives Security Error and fails to load its functions. 

During the HydraCAD install, you get an error saying, "InstallShield Wizard - Unable to find HKEY_CLASSES_ROOT\.DWG registry key.  You may need to repair AutoCAD or reinstall it

Trying the DDL command gives the error; 

Usage: (acad_strlsort <list of strings>)

Error bad argument type: consp nil

When raising to 3D, you get the error message, "Error loading the Error GUI has occurred.  How ironic."

The drawing will raise to 3D, but you won't see the error dialog window.

Trying the Show Model Errors command (SME) produces the same error

When the OK button is clicked from the AutoLIST Setup window, it'll either hang/freeze or crash with a Fatal Error

Unhandled e0434352h Exception at 25CE17Ah

When raising to 3D, the drawing hangs.  On the progress bar at the bottom, it may be stuck at, "Creating entry for mains database"

If you turn off the Show Fittings in Model option found in the 3D Modeling Settings window (3MO command), it likely will create a model.

The only option is to End Task AutoCAD to stop the process.

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 released AutoCAD 2025.1.4 & 2026.1.2 updates which 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. All 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.

Other commands with this error;

Sprinkler Layout dialog (SL command)

Default Dialog Location (DDL command)

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