System.NullReferenceException arises when SXA site manager is under load

[IelyzavetaKalinchuk]

Expected Behavior

No errors arise.

Actual Behavior

SXA site manager breaks when CM server is under load. The following errors arises: Exception: System.NullReferenceException Message: Object reference not set to an instance of an object. Source: Spe at Spe.Client.Controls.PowerShellListView.get_FilteredItems() at Spe.Client.Controls.PowerShellListView.set_CurrentPage(Int32 value) at Spe.Client.Applications.PowerShellResultViewerList.UpdatePage(Int32 newPage)

Steps to Reproduce the Problem

SPE 6.0. Unfortunately, I was not able to reproduce this issue on the clean SXA 1.10 + Sitecore 9.3, because it is necessary that a lot of people work simultaneously in the SXA site manager. I simply investigated the provided memory dump file.

I have provided the customer with the following fix for this issue: public class PowerShellListView : Listview { static object locker = new object(); ----------------------------- _public List<BaseListViewCommand.DataObject> FilteredItems { get { lock (locker) { if (filteredItems == null) { // your code } } } } This fix helped to solve the issue.