Exception when opening a saved session.

[jfkguidant]

Invalid Content: ActiveContent must be one of the visible contents, or null if there is no visible content.\n\n
InvalidOperationException
at WeifenLuo.WinFormsUI.Docking.DockPane.set_ActiveContent(IDockContent value)
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.Activate()
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.SetParent(Control value)
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.SetPane(DockPane pane)
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.SetPaneAndVisible(DockPane pane)
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.SetDockState(Boolean isHidden, DockState visibleState, DockPane oldPane)
at WeifenLuo.WinFormsUI.Docking.DockContentHandler.set_PanelPane(DockPane value)
at WeifenLuo.WinFormsUI.Docking.DockPane.InternalConstruct(IDockContent content, DockState dockState, Boolean flagBounds, Rectangle floatWindowBounds, DockPane prevPane, DockAlignment alignment, Double proportion, Boolean show)
at WeifenLuo.WinFormsUI.Docking.DockPane..ctor(IDockContent content, DockState visibleState, Boolean show)
at WeifenLuo.WinFormsUI.ThemeVS2013.VS2013DockPane..ctor(IDockContent content, DockState visibleState, Boolean show)
at WeifenLuo.WinFormsUI.ThemeVS2013.VS2013DockPaneFactory.CreateDockPane(IDockContent content, DockState visibleState, Boolean show)
at WeifenLuo.WinFormsUI.Docking.DockPanel.Persistor.LoadFromXml(DockPanel dockPanel, Stream stream, DeserializeDockContent deserializeContent, Boolean closeStream)
at WeifenLuo.WinFormsUI.Docking.DockPanel.LoadFromXml(Stream stream, DeserializeDockContent deserializeContent, Boolean closeStream)
at LogExpert.UI.Controls.LogTabWindow.LogTabWindow.RestoreLayout(String layoutXml) in C:\dev\LogExpert\src\LogExpert.UI\Dialogs\LogTabWindow\LogTabWindow.cs:line 1627
at LogExpert.UI.Controls.LogTabWindow.LogTabWindow.LoadProject(String projectFileName, Boolean restoreLayout) in C:\dev\LogExpert\src\LogExpert.UI\Dialogs\LogTabWindow\LogTabWindow.cs:line 1506
at LogExpert.UI.Services.FileOperationService.FileOperationService.LoadFilesWithOption(String[] fileNames, Boolean invertLogic) in C:\dev\LogExpert\src\LogExpert.UI\Services\FileOperationService\FileOperationService.cs:line 221
at LogExpert.UI.Services.FileOperationService.FileOperationService.LoadStartupFiles(IList`1 lastOpenFiles, String[] startupFileNames) in C:\dev\LogExpert\src\LogExpert.UI\Services\FileOperationService\FileOperationService.cs:line 324
at LogExpert.UI.Controls.LogTabWindow.LogTabWindow.OnLogTabWindowLoad(Object sender, EventArgs e) in C:\dev\LogExpert\src\LogExpert.UI\Dialogs\LogTabWindow\LogTabWindow.cs:line 1679
at System.Windows.Forms.Form.OnLoad(EventArgs e)
at System.Windows.Forms.Control.CreateControl()
at System.Windows.Forms.Control.WmShowWindow(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(HWND hWnd, UInt32 msg, WPARAM wparam, LPARAM lparam)

Here is the session file:
{
"FileNames": [
"C:\Tmp\C__Tmp_testlog.txt.lxp"
],
"TabLayoutXml": "\r\n\r\n<DockPanel FormatVersion="1.0" DockLeftPortion="0.25" DockRightPortion="0.25" DockTopPortion="0.25" DockBottomPortion="0.25" ActiveDocumentPane="0" ActivePane="0">\r\n <Contents Count="1">\r\n <Content ID="0" PersistString="LogWindow#C:\Tmp\testlog.txt" AutoHidePortion="0.25" IsHidden="False" IsFloat="False" />\r\n \r\n <Panes Count="1">\r\n <Pane ID="0" DockState="Document" ActiveContent="0">\r\n <Contents Count="1">\r\n <Content ID="0" RefID="0" />\r\n \r\n \r\n \r\n \r\n <DockWindow ID="0" DockState="Document" ZOrderIndex="1">\r\n <NestedPanes Count="1">\r\n <Pane ID="0" RefID="0" PrevPane="-1" Alignment="Right" Proportion="0.5" />\r\n \r\n \r\n <DockWindow ID="1" DockState="DockLeft" ZOrderIndex="4">\r\n <NestedPanes Count="0" />\r\n \r\n <DockWindow ID="2" DockState="DockRight" ZOrderIndex="5">\r\n <NestedPanes Count="0" />\r\n \r\n <DockWindow ID="3" DockState="DockTop" ZOrderIndex="6">\r\n <NestedPanes Count="0" />\r\n \r\n <DockWindow ID="4" DockState="DockBottom" ZOrderIndex="7">\r\n <NestedPanes Count="0" />\r\n \r\n \r\n <FloatWindows Count="0" />\r\n",
"ProjectFilePath": null
}

And the lxp:
{
"$id": "1",
"BookmarkList": {
"$id": "2"
},
"BookmarkListPosition": 300,
"BookmarkListVisible": false,
"Columnizer": {
"TypeName": "LogExpert.Core.Entities.DefaultLogfileColumnizer, LogExpert.Core, Version=1.40.0.0, Culture=neutral, PublicKeyToken=4f1de4c770adbe0a",
"DisplayName": "Default (single line)",
"CustomName": "Default (single line)",
"State": {}
},
"ColumnizerName": null,
"CurrentLine": 0,
"Encoding": "utf-8",
"FileName": "C:\Tmp\testlog.txt",
"FilterAdvanced": false,
"FilterParamsList": [],
"FilterPosition": 486,
"FilterSaveListVisible": false,
"FilterTabDataList": [],
"CellSelectMode": false,
"FirstDisplayedLine": 0,
"FollowTail": true,
"HighlightGroupName": "[Default]",
"FilterVisible": false,
"LineCount": 1,
"MultiFile": false,
"MultiFileMaxDays": 3,
"MultiFileNames": [],
"MultiFilePattern": "*$J(.)",
"RowHeightList": {
"$id": "3"
},
"SessionFileName": null,
"ShowBookmarkCommentColumn": false,
"TabName": "testlog.txt",
"SettingsSaveLoadLocation": null
}

The lxp works fine. I can double click on it.

I can run it under Visual Studio to understand more but not right now.