1. Inserting a hydraulic reference point doesn't erase an existing ref point at the same location

2. New ref points in HydraCALC are not using the values of the HYD ref points.

When I use Pretty Sprinklers, all the nodes that were attached to my sprinklers when using All Ref Points disappeared. 
When trying to get them back by re-running All Ref Points, they don't reappear.

AutoCALC is creating extra node points where there shouldn't be.  In the image below, node 45 shouldn't be created as there's neither a flowing head nor a change in diameter at that point.

'extra node'

'extra ref point'

'extra reference point'

'refpt'

When I use Pretty Sprinklers, all the nodes that were attached to my sprinklers when using All Ref Points disappeared. 
When trying to get them back by re-running All Ref Points, they don't reappear.

Error placing Reference Points or Demand Area annotation... The 3D view ownerDBViewId is not locked.

Step 1a.1 - Error box - missing Pipe Type pointing to Ref 1 & Ref 2

can also be Step 1a.4

Dummy reference points cannot find the dummy ref point block in the drawing's block table. **Possible there's a missing registry entry** Dialog box 52.04

Step 1a.10 - "Attaching Node 2 Elevations" User ID Duplicated Dwg ID Dup for User ID

Duplicated hydraulic ref points

Bad ref point block Dialog box

Pop-up immediately after selecting RTS Points

The location that your document is saved in cannot be used. Please select that folder that you would like RTS data saved to,

When trying to run the calculation, you get the message, 

"The system flow demand of ### exceeds the maximum rated flow as indicated in the Pump Curve for the pump with the inlet of PI and outlet of PO.  The calculation will not continue"

But your flow is a very large number

When running the Line Couplings command (LC), you get the error, "No branch lines found crossing the line(s) you picked", even though it's 100% a fact the lines are intersecting

HydraLIST - Msg #10010

An ERROR5 has occured!  Invalid procedure call or argument error 5

OR

An ERROR76 has occured...  Path not found

The error occured in; Module - RegModule SubRoutine - Set VB Dev

When opening AutoCAD, usually after a fresh install, you're greeted with this error message'

InstallPath registry key not found.  HydraCAD must be re-installed using the current profile.  Defaulting to C:

Run-time Error 339

"Component tab32x30.OCX, spr32x25.OCX, spr32x35.OCX (or a different .OCX file) or one of its dependencies not correctly registered"  "A file is missing or invalid"

System seems to hang at this step, but eventually shows the error;

Hydraulic Calculation - The system flow demand of ####.## exceeds the maximum rated flow as indicated in the Pump Curve for the pump with the inlet of PI and outlet of PO.

The calculation will not continue Calculation failed for an unknown reason

May not be 1a.3 or 2.3, could be anywhere along here.

All layers where objects should appear white in AutoCAD will randomly turn brown in color (colors 18, 19, 248, or 249)

Note the pipe dimension and main piping in the image above are brown instead of white.

You are not currently authorized to use this Hydratec Product.   Lack of authorization.

When clicking the Calculate button or the OK button from the Pre-Calc Questions window, you get a Runtime-error 5,

Run-time error '5': Invalid procedure call or argument

Double-clicking your HydraCALC icon makes nothing happen.  You do not see HydraCALC open onscreen nor on your taskbar.  HydraCALC does not open other than in the task manager.

If you open your task manager and see the app "Hyd_prog.exe" open but not on your taskbar, then the application is stuck in purgatory.

Another possibility may be that it's on the taskbar but not on your screen.  That means it's open but offscreen. 

See this HydraCARD to fix that issue;  HydraCARD 565 only AFTER you've checked on the solution below.