We are working to recreate this issue in a small test project as the issue is still happening. 

Thanks.

Hi,

The error message says UserControl. Is this a UserControl designer you are opening up? Or a Form with a UserControl on it?

Do you know specifically which control(s) is causing this error?

This is probably a bug. It looks like simply opening the form/UserControl in the designer is trying to change a property and thus dirty the form, but it can't do so because the form is read-only because it's not checked out. But opening up a designer should never by dirtying a property, so if that's what is happening, it's a bug.

If I am right, then when you check out the file and then open it, it will open up without an error, but you will see a "*" at the end of the file name in the tab for that file in Visual Studio, indicating that some property has been dirtied, even though you just opened up the designer without changing anything.

But we would have to know which control it is in order to fix it. Are you able to duplicate this behavior in a small sample project?

Sometimes If you have an infragistics control on a form that is checked in TFS source control and try to view the form in design mode you get the following error

The control System.Windows.Forms.UserControl has thrown an unhandled exception in the designer and has been disabled.

Exception: Unable to checkout the current file. The file may be locked, or you may need to check the file out manually.

Then when you click ok to continue, you see the form with a bix red bordered box and a red X that says Sytem compnentMod where the infragistic control should be.

If you check out the form you can view it with no problem. We need to be able to view the form without checking it out.

Again we are using visual studio 2010 with infragistic controls version 10 volume 2