DataTable internal index is corrupted

I just had the same issue while importing rows, as it seems, calling DataTable.BeginLoadData before the insert fixed it for me.

Edit: As it turns out, this only fixed it on one side, now adding rows throws this exception.

Edit2: Suspending binding as suggested by Robert Rossney fixed the adding problem for me, too. I simply removed the DataSource from the DataGridView and readded it after I was done with the DataTable.

Edit3: Still not fixed…the exception keeps creeping up in all different places in my code since Thursday…this is by far the strangest and most f****ing bug I’ve encountered in the Framework so far (and I’ve seen many odd things in the 3 years I’ve been working with .NET 2.0, enough to warrant that not a single of my future projects will be build on it). But enough of ranting, back on topic.

I’ve read through the whole discussion at the Microsoft support forums and I’ll give you a brief summary of it. The original bug report originates in ’05.

• March ’06: Bug is reported the first time, investigation starts. Throughout the course of the next year it is reported in different forms and different manifestations.
• March ’07: Finally a hotfix with number KB 932491 is released (don’t get your hopes up), it links against a download of an completely irrelevant looking hotfix, or at least so it seems. Throughout the next months many report that the hotfix does not work, some are reporting success.
• July ’07: Last sign of live from Microsoft (with a complete useless answer), beyond this point is no further response from Microsoft. No further confirmations, no attempts on support, no requests for more information…nothing. Beyond this point there’s only community related information.

No seriously, this sums it up in my opinion. I was able to extract the following information from the whole discussion:

• The DataTable is not Thread-Safe. You’ll have to Lock/Synchronize it on your own if you have Multi-Threading anywhere on it.
• The corruption of the index happens somewhere before the actual exception is thrown.
• One possible corruption source is either an applied Expression or an applied Sort.
• Another possible source is the DataTable.ListChanged() event, do never modify data in this event or any event which spawns from it. This includes different Changed events from bound controls.
• There are possible issues when binding the DefaultView against a control. Always use DataTable.BeginLoadData() and DataTable.EndLoadData().
• Creation and manipulation of the DefaultView is a writing operation on the DataTable (and its Index), the Flying Spaghetti Monster knows why.

The possible source of this is most likely a race condition, either in our source code or in the code of the framework. As it seems, Microsoft is unable to fix this bug or has no intention to. Either way, check your code for race conditions, it has something to do with the DefaultView in my opinion. At some point an Insert or a manipulation of the data is corrupting the internal Index because the changes are not properly propagated through the whole DataTable.

I’ll of course report back when I find further informations or additional fixes. And sorry if I get a little bit emotional here, but I’ve spent three days trying to pinpoint this issue, and it slowly starts to look like a good reason to get a new job.

Edit4: I was able to avoid this bug by completely removing the binding (control.DataSource = null;) and re-adding it after the loading of the data is completed. Which fuels my thought that it has something to do with the DefaultView and the events which spawn from the bound controls.