diff --git a/www/manager6/lxc/SnapshotTree.js b/www/manager6/lxc/SnapshotTree.js
index 8969e974..df5b31cf 100644
--- a/www/manager6/lxc/SnapshotTree.js
+++ b/www/manager6/lxc/SnapshotTree.js
@@ -96,6 +96,15 @@ Ext.define('PVE.lxc.SnapshotTree', {
 
     },
 
+    listeners: {
+	beforestatesave: function(grid, state, eopts) {
+	    // extjs cannot serialize functions,
+	    // so a the sorter with only the sorterFn will
+	    // not be a valid sorter when restoring the state
+	    delete state.storeState.sorters;
+	}
+    },
+
     initComponent: function() {
 	var me = this;
 
diff --git a/www/manager6/qemu/SnapshotTree.js b/www/manager6/qemu/SnapshotTree.js
index c35b9c0c..ea14d0fe 100644
--- a/www/manager6/qemu/SnapshotTree.js
+++ b/www/manager6/qemu/SnapshotTree.js
@@ -94,6 +94,15 @@ Ext.define('PVE.qemu.SnapshotTree', {
 
     },
 
+    listeners: {
+	beforestatesave: function(grid, state, eopts) {
+	    // extjs cannot serialize functions,
+	    // so a the sorter with only the sorterFn will
+	    // not be a valid sorter when restoring the state
+	    delete state.storeState.sorters;
+	}
+    },
+
     initComponent: function() {
         var me = this;