ERROR: No fittings were found on the selected pipe

When inserting a listing tag on a pipe, you get the error, "Invalid color number"

Command Failure for External Command... Revit could not complete the external command.

Revit could not complete the external command... x must be a finite number 

The diameter tag HANDLE is 0000 this number is used to determin if the pipe is sloped - yielding an incorrect pipe length. Move Line / Move Main make the diameter tag HANDLE be 0000

Revit could not complete the external command... The 3D view ownerDBViewId is not locked

Revit could not complete the external command... Autodesk.Revit.Exceptions.InvalidObjectException

Revit could not complete the external command... Revit encountered a Attempt to modify the model outside of transaction...

Command Failure for External Command... System.NullReferenceException

Command Failure for External Command... System.NullReferenceException

Revit could not complete the External Command... System.NullReferenceException

Revit could not complete the external command     System.NullReferenceException

 Line / Main tags are blocking items behind the text / tags are not transparent

Vertical pipe issue.  Switching back to Edit Mode (S2D) leaves HydraPipes in Hydrapipe layer.

Then when trying to show system model again (S3D) you get an AutoCAD message box "Please Switch to Edit Mode"

After setting specific linetypes for your piping, pretty pipes doesn't match the linetype of your pipe.

The pipe noted should show a HIDDEN pretty pipe, similar to the one below it

When trying to use Cleanup Tags, this error appears and nothing else happens (i.e. the tags were not cleaned up)

When printing a final calculation, the font doesn't show fraction symbols for ¼ (quarter), ½ (half), or ¾ (three-quarters)

They're replaced with ?.840, ?1.050, and ?1.660

These should look like this;

Of note, if using HydraCAD for AutoCAD, you get similar results on riser nipples/vertical pipes 

When starting the Pretty Pipes command, you get an Unhandled Exception error including 'Could not find a part of the path'

Another error may mention blockoffsets.dat

When plotting to Bluebeam document, some HydraCAD drawing entities show up blacked out.

AutoCAD view;

PDF generated by Bluebeam;

When attempting to create a 3D model, you get the error; Please switch to System Model to Annotate Drops and Sprigs plus

System.NullReferenceException: Object reference not set to an instance of an object

at HCADexports.RevitConversion.create_hydrapipes_from_db()

at HCADexports.RevitConversion.create_hydrafittings_from_db(List'1 pipes, List'1 heads)