diff --git a/trunk/CHANGELOG.txt b/trunk/CHANGELOG.txt
index 63ea27355..00a3993cb 100644
--- a/trunk/CHANGELOG.txt
+++ b/trunk/CHANGELOG.txt
@@ -12,6 +12,7 @@ Process Hacker
    * Shows function file and line numbers where available
  * FIXED:
    * #2785648 - "cursor down crashes PH"
+   * #2790404 - "System.InvalidOperationException"
    * Incomplete or inaccurate thread call stacks
    * Windows 7 BSOD
    * Crash upon executing terminator test M1
diff --git a/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs b/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
index 737a161f8..db5f8ec4d 100644
--- a/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
+++ b/trunk/ProcessHacker/Components/ProcessTree/ProcessTreeModel.cs
@@ -59,8 +59,10 @@ namespace ProcessHacker
             // Add the process to the list of all processes.
             _processes.Add(item.Pid, itemNode);
 
-            // Find this process' children and add them.
-            foreach (ProcessNode node in _roots)
+            // Find this process' children and add them.  
+            ProcessNode[] roots = _roots.ToArray();
+
+            foreach (ProcessNode node in roots)
             {
                 if (node.ProcessItem.HasParent && node.PPid == item.Pid)
                 {