I have a process flow that resembled the following.

Machine
----Rule Group
    ----Rule
        ----Action

Such that machines have many rule groups, which each have many rules, which each have many actions.

Our UI is relatively straight forward, and models this paradigm, we have a section that allows the user to edit the details of the level they are on, and grid that shows what child items are attached to the current item.  Each line item in the grid opens up a new window with that item editable, and its children in a grid, on and on down until we reach actions which have no children.

I am running across an issue where if I start high enough in the chain, say RuleGroup, and pop up new windows to edit my way down, once I reach a certain point, the new windows stop being created.  There are no errors or exceptions, the windows just never render, regardless of how many times, or how long I wait to click the button again.  Now if I go to the offending form directly, and open up a child it will come right up.  This behavior is odd, but I think I have it narrowed down to 3 levels of forms.  The base form, and 2 levels of children before there are issues rendering new forms.  I have also noticed this behavior in the past with message boxes, but since we use them to show exception messages to the developers I always assumed the exception had prevented the rendering of the messagebox window, now I'm not so sure that is the case.

We are using 6.3.13.  The browser I am noticing this behavior in is IE8 (what our clients require, yuck).  I will test in firefox and chrome this evening to see if it reproduces the behavior. Also, I am using ShowDialog() for almost every child form I show because I want modal behavior.

My question is, is there a limit to the number of forms, or the nesting depth of forms in visual web gui?  If there is, is there any way around it?  If there isn't, why would I be seeing this behavior in my application?

Thanks yet again for your time, and keep up the good work, your product makes RIA development fun again.

Hi Palli,

Thanks for getting back to me so fast.  I created a sample project that went 5 levels deep with modal forms all that could invoke message boxes, but that did not reproduce the issue.  I also retested my own project this morning, and I did not see the same issues I saw the other day in that section of the application.  I will keep an eye on this, I am certain that this has happened before in other portions of the application, but we haven't been able to really nail it down, since when one developer notices it, we can't reproduce it on another developers machine. I'm afraid it is an issue that our customers will come across, but I can't seem to get any consistency on my end to nail down what might be causing the issue. 

If there is in fact an issue, it might have something to do with Close() not freeing the form for garbage collection or something to that effect, but at this time I don't have any hard evidence of such a defect.

If you are aware of any best practices or gotchas with form generation and cleanup please let me know.