Yes, the error occurs only after updating to 4.0.7200.29. No code changes have been made (except updating other IS controls).

Any progress on this?

Yes, it helps explain the problem, but it will not help with our situation.

We have multiple "widgets" on a screen and this box needs to cover the entire dashboard. Widgets and other controls may be nested, so the solution may be to find another control.

Thanks.

Any progress on this?

I showed you in the obfuscated code where you are setting the scrollbar height. You should be able to refer to the base code to find where you are setting this value.

You wrote back in March "We never resize the scrollbar" - obviously, this is not a true statement. The code should not be setting the height, but it is clear from the image that it does.

If I get time, I will attempt to recreate a sample project, but you now know this is an error in your code.