Revit reproducibly crashes in PickPoint (minimal test case included)

[cwaluga]

The bug can be reproduced as follows (Revit 2020.2, but bug can also be observed in 2019):

• open the attached file MinimalTestCase_PickCrash.rvt (any other file should work as well)
• run the Macro PickExample.CrashMe in a 3D view. The code is really simple:
  

  try
  {
  	Application.ActiveUIDocument.Selection.PickPoint(ObjectSnapTypes.None, "Click on sides of view cube and then somewhere else!");
  }
  catch(OperationCanceledException) {}

• click on any side of the view cube (e.g. "RIGHT")
• click into the view and you should get a message box "Revit - A serious error has occurred. The current action has been cancelled. It is strongly recommended that you save your work in a new file before continuing. Would you like to save a recovery file? Yes/No"
• clicking "No" fortunately lets you resume the session, however it looks terrible to users if something like this happens out of nowhere, especially if you are asked to save or fear data loss.
• attaching a debugger reveals that the following exception is thrown immediately before the crash: "Exception thrown at 0x00007FF9F9FCA388 in Revit.exe: Microsoft C++ exception: ModificationOutsideTransactionException at memory location 0x00000019915081B0."

[jeremytammik]

Dear Cwaluga,

Thank you for your report, minimal reproducible case, succinct and clear description.

Sorry to hear about this.

I logged the issue REVIT-156495 [PickPoint click on view cube crashes Revit] with our development team for this on your behalf as it requires further exploration and possibly a modification to our software. Please make a note of this number for future reference.

You are welcome to request an update on the status of this issue or to provide additional information on it at any time quoting this change request number.

This issue is important to me. What can I do to help?

This issue needs to be assessed by our engineering team and prioritised against all other outstanding change requests. Any information that you can provide to influence this assessment will help. Please provide the following where possible:

• Impact on your application and/or your development.
• The number of users affected.
• The potential revenue impact to you.
• The potential revenue impact to Autodesk.
• Realistic timescale over which a fix would help you.
• In the case of a request for a new feature or a feature enhancement, please also provide detailed Use cases for the workflows that this change would address.

This information is extremely important. Our engineering team have limited resources, and so must focus their efforts on the highest impact items. We do understand that this will cause you delays and affect your development planning, and we appreciate your cooperation and patience.

Best regards,

Jeremy

[cwaluga]

Hi Jeremy,

Thanks! One thing about your title: the problem is not linked to clicking the cube but afterwards clicking somewhere in the clear parts of a side-aligned 3D view (where the cursor indicates that picking is not available).

Regarding your other questions: The issue is not super-critical for us, but since it is such a widely-used function it might be a good idea to secure it soon. Even more so, because it sounds pretty suspicious that the Revit backend seems to attempt modifications to the DB in a pick operation.

[jeremytammik]

Thank you again for reporting this!

The development team analysed the ticket I submitted for it, REVIT-156495 [PickPoint click on view cube crashes Revit].

They reproduced the issue, determined the need for a code fix in a future version of Revit, and created a new ticket REVIT-156660 [PickPoint click on view cube crashes Revit] to implement that.

Happy holidays!

Jeremy