When attempting to insert a pipe dimension you get the error "Invalid option keyword"

And the command prompt says "Enter an UNDO control option" with the dialog showing your choices

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 opening AutoCAD, you get an error saying "a software problem has AutoCAD to close unexpectedly"

Upon reviewing the file it's crashed on, it shows HCAD_MAKEFIGHANGERLIST as the culprit

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

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

When trying to open a drawing file, you get this error; 

DAO Server - Error DBOpen4

Call from 'hcad_fignames'.

Path:'C:\HES\HydraCAD\Ver50\AutoListElements\Data\Setup\MdbTRANS.mdb'

DAO Error:  Unrecognized database format

C:\HES\HydraCAD\Ver50\AutoListElements\Data\Setup\mdbtrans.mdb'

When you click OK, AutoCAD crashes out

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

AutoCAD view;

PDF generated by Bluebeam;

When re-opening a calc file generated by Hcad for Revit, you get a Runtime-error 62, Input past end of file

Followed by an 'error during load_data' message.

NOTE:  After clicking OK, the job will open to blank data.  Close the file.

DO NOT CLICK 'YES' TO SAVE YOUR DATA otherwise you will lose all your data and there is no way to recover it.

Drawing looks strange, piping looks hollow and sprinkler heads a little off and Acad background looks greyish/grayish.

Drawing also seems to lag when panning, processes take longer

Calculation stops at Step 1a.4 - calcing total lengths

Can be accompanied with a "Runtime error 5 - invalid procedure call or argument" or "Runtime error 6 - overflow"

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