Revit could not complete the external commad... Method not found

While attempting to raise to 3D, you get this error message;

Exception Occured at AddURLToHyperlinks::HydraHeads

The drawing will still raise to 3D but you may not have sprinkler heads visible.

(TYPE_E_CANTLOADLIBRARY)

679327F1-F31E-488D-8FBC-124C4F6F588E

DAO32ServerLib.DaoComObj

When trying to insert a Hydraulic demand block (Compact/Standard/Expanded) (IHD command) and after selecting the .WXF file to use;

You get the error message;

Error: bad argument type: numberp: DATAFILE

And the command kicks you out.

After setting up a fitting in the Parts Tree then trying to Insert Fitting, you get the Unhandled Exception error below

eLockViolation

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

eOnLockedLayer

Pretty Sprinklers does not seem to work with sidewall heads.

Glyphs used to indicate the component type (Line/Main/Armover/Underground) that riser nipples are to be listed as remain on drawing even after command is closed

Component TABCTL32.OCX or one of its dependencies no correctly registered: a file is missing or invalid Unhandled Exception n/a

Revit could not complete the external command... System.ArgumentException

When trying to run Spacing and Layout, this error appears. Revit could not complete the external command... System.NullReferenceException

Also could encounter this error:

Double-Clicking on a riser nipple, or using the Edit Riser Nipple command (ERN) briefly displays the edit riser nipple dialog, which then closes

Revit could not complete the external command... System.NullReferenceException

When using the Continuous option, after I am done I get an error and all the changes are erased.

All the valves listed are red and can't be imported

When Revit retrieves the content from ACAD it is recognizable but not really usable.  It looks all wonky / messed up.

Retrieve HydraCAD Revit MEP Content button is missing

Greyed out options in the Addin Assistant and ribbons do not appear in Revit

When opening HydraCAD and trying to open a drawing or a template, you get the error message; 

Also happened when layers were isolated trying to burst objects

'unrecognized version and cannot be read'

When attempting to run the NWCOUT command, you get an 'unknown command' error message;

When attempting to setup a sprinkler head, after clicking OK in the definition window, the command prompt looks like this and no sprinkler head is inserted;