Exporting a Persistent Model gives the following message.  More than like the PM drawing gets saved anyway.

Cannot Save!  drawing path and filename might be OPEN.  Pleace (sic) close amd (sic) try again. 

*Should be "Please close and try again"

No error reported for FSC even when maximum length is clearly exceeded

If you view the FSC properties, it's possible the HoseLength and MaxNumberOfBends values are not set.

This error appears immediately when trying to run Auto Stocklist, the dialog box never appears. 

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

No error, but in inserted Valve is misaligned or not in the desired direction. There may also be some other visual issues. 

When using Rapid Pipe/Rapid Line/Rapid Main, you do not see the tooltip which indicates your future pipe lengths

Bad location of K-Factor

When trying to run a calc for the system, this error appears: 

After using the Spacing and Layout tool, the pipes and sprinklers are modeled but are not connected properly to each other. 

Compile error in hidden module: CollectInvData

No error, but when opening the file menu and opening Revit, the program freezes or stutters anywhere between 10 seconds - 1 minute. 

Processing gets stuck / freezes at optimization for pipe type(s)

Unable to load defaults during HydraCALC Setup. Occasionally will give an error, but most commonly nothing will be filled in. 

Inserted sprinkler is disconnected / malfunctioning & the branchline pipe is missing

Revit could not complete the external command... No work plane set in current view

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

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