When starting the AutoCALC process, you get the error Unhandled exception has occurred in a component of your application

Key cannot be null

Parameter name: key.

Expanding DETAILS shows this information;

Application does not support just-in-time (JIT)
debugging. See the end of this message for details.

************** Exception Text **************
System.ArgumentNullException: Key cannot be null.
Parameter name: key
   at System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add)
   at HCAD_HUI_CALC.CalcClass_Utilities.GetNodesOfPipesThatAreVertical(String FitID, Calc_File myCalcFile)
   at CalcingNameSpace.AutoCalcForm.MakeCalcFiledataPart1(Database db, Calc_File& MyCalcFile)
   at CalcingNameSpace.AutoCalcForm.SetupCalcFile()

When running AutoCALC, the process stops around step 2.4c and you get a Run-time error 457, "This key is already associated with an element of this collection

Command Failure for External Command... System.NullReferenceException

Step 9a.1 - Runtime Error 62 Input past end of file.

Step 9a.1 - Saving Raw Calc Data Auto- Program Load Error Could not initiate process called for by \Hes\HydraCalc\Ver50\Programs\Hyd_Prog.exe

Unhandled exception: Length cannot be zero

No message, but grid does not get set up with L and R markers, even though a grid. Pipe mislabled as to Input Type

Autopeak peaking hydracalc

Runtime Error 6 when Attaching Fittings

Fitting is a RED. COUPLING @ node DAB0C connected to pipes D9FE8 :D9FE2.

Trying to run a auto calc from a drawing.  How do I find the referenced pipes?

When attempting to open the HydraCALC pipe sizer in order to use the Pipe Scheduler in HydraCAD, you get an error indicating that a newer version of HydraCALC is required. It will indicate that v50.43 or newer is needed, but the user may be on a newer version already.