Trying to run a calculation, you get the error;

Could not Initiate Process called for by: (name of the problem file), ie. HydCalc.exe or Miscfunc.exe

Reviewing the results you notice a discrepancy between the k-factor of an equivalent k versus a sprinkler head using that equivalent k-factor

In the example below, EQ02 has a k-factor of 5.37.  Reference point 1 is supposed to use the k-factor of EQ02 (5.37) but in fact is using a different value (5.36).

When double-clicking a .WXF file, you get the error, "An error has occurred and HydraCALC cannot be loaded;

Path:  

File: 

During a HydraCALC re-install, you are presented with this error message.  After clicking OK, you have to finish the incomplete install process 

Error: -1605  This action is only valid for products that are currently installed

Selecting any of the three choices below will  result in the same error.

When trying to open HydraCALC, you get Run-time error 9 - Subscript out of range

When trying to open a .WXF file by double-clicking it, you get this error message;

"The requested operation requires elevation"

The file can be opened if using HydraCALC to open the file by going to the menu [File|Open]

Double-clicking your HydraCALC icon makes nothing happen.  You do not see HydraCALC open onscreen nor on your taskbar.  

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.

If you see entries here, use END TASK to get rid of them.

Another option 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.

When running a calculation, the value for "pressure required" shows a negative value.

After calculating the system, the results show, "Your System Has a Deficit"

System is -nan(ind) psi over the Water Supply Curve

HydraCALC is calculating the equivalent lengths wrong