When selecting "Retrieve Part Num/Desc <" from the sprinkler Block Definition window, you get the error;

Error: bad argument type: stringp nil

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 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 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

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

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)

When starting the AutoLIST process, the message box shown below pops up.  The process "pretends" to continue through, but when HydraLIST opens, it's completely blank.

Re-run Autolist with the drawing starting on the ground. Current run will not include any FSC information in the MISC tab in HydraList.

When viewing the final calc printout, the info sheet shows the line,

text1(35) - invisible