"Unknown error" when adding shapes to crossfunctional flowchart in Visio online

[superman]

For a while I have been having problems with editing Cross Functional Flowcharts. This issue is only present when using the Microsoft Visio Online version of Visio. In my case i am currently running Online Plan 2 MSO version 16.0.11929.20836 (32-bits). I also have tested this with earlier versions of Visio (tested 2010, 2013 and 2016), but with those versions i cannot reproduce this problem.

I first noticed this when trying to edit some of my existing diagrams, but after some testing it turns out i can even reproduce this when a create a whole new diagram from scratch. So to me, this is more and more looking to simply be a bug in Visio.

To reproduce this issue i follow this scenario :
-Open the Visio application
-Create a new basic diagram
-In the shapes pane select "More Shapes > Flowchart > Cross-Functional Flowchart shapes"
-Insert a swimline in the document
-Add a basic shape into the swimlane (for example a 'rectangle')
-Add a second basic shape into the swimlane

On adding the 2nd basic shape to the swimlane a dialog appears showing the text "An unknown error has occurred". I have added a screenshot of this message as attachment, only note that my Visio is set to the Dutch language so i have translated the text of the message. 

I am really staring to run out of ideas, so far i have been unable to find any similar reports of this issue. Since i can only reproduce with a specific version of Visio, and even when creating a completely new document i am starting to get the idea this is a bug in Visio. Or am i just doing something wrong, and really missing the obvious here??

Any help would be greatly appreciated!

[Paul Herber]

Looks like someone is being over-zealous in specifying what shapes can be added to a x-func flowchart diagram. The spec said shapeA .. shapeP so anything else must be an error.