C# – DatagridView Not Displaying the error icon or error text

Looks like I found it: http://seewinapp.blogspot.com/2005/09/is-your-autoscroll-too-auto.html

I overrode the RowChanged event on the DataTable, stored the FirstDisplayedScrollingRowIndex, invoked a delegate method with that index as the argument, and then reset the FirstDisplayedScrollingRowIndex to that argument inside the delegate method. It turns out that auto-scroll doesn't occur until after all events have been fired, so it's useless to try to hack it inside an event. The delegate works because it is invoked after the events.

Start debugging, as soon as you've arrived at a breakpoint or used Debug > Break All, use Debug > Windows > Modules. You'll see a list of all the assemblies that are loaded into the process. Locate the one you want to get debug info for. Right-click it and select Symbol Load Information. You'll get a dialog that lists all the directories where it looked for the .pdb file for the assembly. Verify that list against the actual .pdb location. Make sure it doesn't find an old one.

In normal projects, the assembly and its .pdb file should always have been copied by the IDE into the same folder as your .exe, i.e. the bin\Debug folder of your project. Make sure you remove one from the GAC if you've been playing with it.