Deletes the posted failure message associated with a given FailureMessageKey. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2011 
Syntax
| C# | 
|---|
   |  
| Visual Basic | 
|---|
   |  
| Visual C++ | 
|---|
   |  
Parameters
- messageKey
 -  Type:  Autodesk.Revit.DB FailureMessageKey  
The key of the FailureMessage to be deleted. 
Remarks
 If code that previously has posted a failure is executed again or otherwise detects that failure conditions do not exist anymore and the failure is not longer relevant, it should delete a failure message in order to let transaction to be committed. In order to delete the failure, it should invoke this method with a message key that was returned when the failure was posted. 
 Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentException | messageKey is invalid | 
| Autodesk.Revit.Exceptions ArgumentNullException | A non-optional argument was NULL | 
| Autodesk.Revit.Exceptions ModificationForbiddenException | The document is in failure mode: an operation has failed, and Revit requires the user to either cancel the operation or fix the problem (usually by deleting certain elements). -or- The document is being loaded, or is in the midst of another sensitive process. | 
| Autodesk.Revit.Exceptions ModificationOutsideTransactionException | The document has no open transaction. |