Hi Dilyan,

Thank you for quick response first of all.

I tried to update you project to simulate the scenario and it's not reproduced.

But in our case it also happens once in a while, so maybe if you'll try to execute this small app for long time release compiled maybe some day the crash will occur. My guess, it's issue of timing.

I'll try to describe what complexity we have in our project, maybe it will help you to understand when the crash could happen.

First of all our VitualGrid uses custom DataProvider.

The view model knows this DataProvider and accesses the virtual grid via DataProvider.ParentGrid.

View model has 2 DispatcherTimers:

- The first one monitors logs that shown in VirtualGrid and on its tick (every 1 sec) calls DataProvider to refresh its data.

- The second one on its tick (every 1 sec) scrolls to the last line in the log and sets this line as selected on ScrollFinishedCallback.

For additional, view model  subscribed to some events(we use Prism events platform) and on their handling it calles via DataProvider: DataSource.Clear() and

ParentGrid.UnselectAll();

ParentGrid.Reset();

ParentGrid.SelectedIndex = -1;

methods

For additional, view model implements filtering and search functionalities, but the crash happens only when ScrollRowIndexIntoViewAsync executed every second (we call it tailing mode) and in between the file replaced and all described above.

Let me know if it helped you to understand or recreate the scenario.

Otherwise, I'll try to find some time and create a small isolated project with the full flow I described.

For a while, I removed a call to ParentGrid.Reset called from DataProvider and added try catch pattern around ScrollRowIndexIntoViewAsync call. But still I'd like to assure you that lack of null check on this.MainPanel.ScrollRowIndexIntoViewInternal inside RadVirtualGrid could be an issue sometimes.

Thank you and best regards,

Maria Adamsky.