System.ComponentModel.Design.ExceptionCollection

Question

I'm using the Ribbon control located on CodePlex, and following the tutorial located here . Once I add the reference, and the proper code in the designer I get this error when I try to view the form:

Exception of type 'System.ComponentModel.Design.ExceptionCollection' was thrown

And I cant figure out what I'm doing wrong. Anyone worked with this control and know how to resolve this issue?

Look at the Exceptions property to see what exceptions were thrown. — Hans Passant, Mar 06 '12 at 12:17
Not to sound like a noobie but how would I go about doing that? When I double-click to see the form is when I get that error, the form wont load — PsychoCoder, Mar 06 '12 at 15:58

score 34 · Accepted Answer · answered Mar 06 '12 at 17:50

Interesting; I just ran into this same issue with one of my own forms; which is how I found your relevant and recent question.

Here's how I solved it:

Open two instances of Visual Studio. Open the same project in both.
In one instance, goto Debug->Exceptions and enable all the 'Thrown' options to stop at first chance exceptions. This will stop the debugger when the exception is generated.
In the same instance, select Debug->Attach to Process, select devenv.exe.
In the other instance, open the form to cause the exception
With any luck the first instance should stop somewhere that yields a more relevant exception.

In my case it turned out to be something that I should have conditioned with:

if (!DesignMode)
{
  // Do something that should only happen at runtime
}

Don't forget turn turn off all those 'Thrown' options later.

I followed your instructions and found the underlying exception, it's an NullReferenceException in the Ribbon control. Now need to figure out how to fix it. — PsychoCoder, Mar 07 '12 at 05:02
For Step2 'Debug->Exceptions' this can be found under Debug->Windows->Exception Settings for newer Visual Studio 2017/9 — sonyisda1, Jun 27 '19 at 14:40

score 5 · Answer 2 · answered Feb 16 '16 at 11:28

5

A workaround for me was:

Right-click on the form and 'View Code'
Keep the code loaded in the editor and then attempt to view the designer again.

This feels very glitchy and I cannot confirm whether it's a problem with my code (as I'm working on an entirely new codebase) or whether it's a VS2012 bug. If I find out, I will report back.

answered Feb 16 '16 at 11:28

dev'd

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For me it was kind of similar, but opening the code-behind wasn't enough. I had to open the designer code (yourformname.designer.cs) in the visual studio editor - and then the designer magically worked! Really weird. – Nicolas Jan 15 '21 at 11:25

score 4 · Answer 3 · edited May 23 '17 at 12:10

Since the solution outlined by pilotcam didn't work for me, I took a different approach:

Make a SVN commit for the file.
Open the “*.designer.cs” file of the form that shows the error in source view.
Remove larger blocks of form element declarations.
Fix all compilation errors with ReSharper (i.e. ensure that nothing is red anymore on the side-indicator).
Save the file. No need to compile.
Open the Windows Forms Designer of the form.
If the error still shows up, do a SVN revert to go back to the initial state.
Repeat steps 2 to 7 until the error does not show up anymore.
Now you’ve encircled the erroneous child control that causes the error.
Repeat steps 2 to 7 with a smaller amount of controls you remove, until you have only one control left.

In my case it was a user control inside a group control inside a tab control, so I first identified the tab control, then the group control and then the user control.

You could isolate the user control inside a new form to further investigate. In my case it was rather easy; I put checks for design mode around most of the functions inside my control to ensure the code only gets executed if the control is not in design mode.

This fixed my error.

Even though the accepted answer is good, this one is very good too. Not really related to Visual Studio and the exception defined in the question but totally relevant in the context of "How to solve a problem" with tools. In my case, after a commit and then deleted a couple of lines where I thought the problem was, I finally found something interesting. I was able to isolated the error. I already knew your suggestion but I was not able to instinctively apply it without reading your answer and then remembering me how to think :D Thanks! — Samuel, Feb 03 '16 at 18:59

Sleephead · Answer 4 · 2015-02-06T09:36:59.970

2

I had the same issue and none of the above answers solved the problem.

At the end, emptying the "bin" folder and rebuild has worked for me.

edited Feb 06 '15 at 09:36

answered Feb 05 '15 at 10:22

Sleephead

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5

score 0 · Answer 5 · answered Jul 04 '14 at 12:34

Let me add two more cases when such exception can happen, along with when control tries to do something that is not allowed under design mode:

When it's impossible to compile the user control.
When designer code contains multiple similar (or identical) lines with initialization of same controls or properties, this can easily happen on merge.

All that cases produce same extremely meaningful error message, and in this particular two debugging of Visual Studio won't help, so I just ended up with bisecting my designer code.

score 0 · Answer 6 · edited Apr 27 '17 at 16:13

0

[ReadOnly(true)]

[Browsable(false)]

Above all properties worked for me

edited Apr 27 '17 at 16:13

Paul Roub

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answered Apr 27 '17 at 16:09

JustSomeGuy

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System.ComponentModel.Design.ExceptionCollection

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