Some of my saved session documents fail to open, displaying this error message:

"Cannot open session document"

I have deleted them and recreated them ... and recreated the same error

Per https://support.microfocus.com/kb/doc.php?id=7024722 I have enabled logging, and in the resulting Workspace.log file, the key error message appears to be:

Connection keyword is invalid for the current connection type

What clue does this message offer, in terms of what I would do next to trouble-shoot?

Contents of Workspace.log:

2021-03-01 13:01:27.4958|INFO|Attachmate.Reflection.Core.ApplicationState|Loaded workspace window settings: C:\\Users\\testuser\\AppData\\Roaming\\Micro Focus\\Reflection\\Desktop\\v16.2\\Frame.settings
2021-03-01 13:01:27.5460|INFO|Attachmate.Emulation.Frame.FrameApplication|Loaded default actions access settings
2021-03-01 13:01:27.8120|WARN|Attachmate.Reflection.Core.PCISettingsProvider|Failed to loaded PCI/DSS settings: C:\\Users\\testuser\\AppData\\Roaming\\Micro Focus\\Reflection\\Desktop\\v16.2\\PCIDSS.settings
2021-03-01 13:01:27.8120|INFO|Attachmate.Reflection.Core.PCISettingsProvider|Loaded PCI/DSS settings: C:\\Program Files (x86)\\Micro Focus\\Reflection\\Configuration\\PCIDSS.settings
2021-03-01 13:01:27.9123|INFO|Attachmate.UIFramework.CustomUI.ActionResourcesManager|Reading action resources file: C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\CustomUI\\ActionResources
2021-03-01 13:01:29.1876|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects' as references
2021-03-01 13:01:29.1876|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'MSHTML' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'SHDOCVW' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Object library not registered
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects.Emulation.IbmHosts' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects.Emulation.OpenSystems' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2827|INFO|MicroFocus.Utilities.CentralManagement.Legacy.Rsg.RsgSessionMgr|Attachmate.Emulation.Frame id 3544: RSG Session Manager is initializing.
2021-03-01 13:01:29.2827|INFO|Attachmate.Reflection.Core.Actions.OpenAction|Attachmate.Emulation.Frame id 3544: [[[[OP]]]] OpenAction OpenDocument Start 2355
2021-03-01 13:01:29.8307|INFO|Attachmate.Emulation.Frame.RibbonSessionUiHelper|Loaded UI file C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\CustomUI\\Reflection2007.VT.Ribbon.xuml
2021-03-01 13:01:30.8710|INFO|Attachmate.Services.InputCaptureService|End-of-input scan timeout is 60 milliseonds.
2021-03-01 13:01:30.9022|INFO|Attachmate.Plugins.Themes.ThemesPlugin|Applied theme C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Themes\\Classic\\Reflection2007.VT.themex to created document file:///C:/Users/testuser/Documents/Micro Focus/Reflection/serial.rdox
2021-03-01 13:01:30.9335|INFO|Attachmate.Utilities.KeyboardMapper.KeyboardMap|Successfully loaded Keyboard Map: [C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\default VT.xkb]
2021-03-01 13:01:30.9335|INFO|Attachmate.Utilities.MouseMap.MouseMap|Successfully loaded Mouse Map: [C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\Default VT.xmm]
2021-03-01 13:01:31.0558|INFO|Attachmate.Utilities.ActionLogger|Executed action: DocumentViewOpened, parameters: file:///C:/Users/testuser/Documents/Micro Focus/Reflection/serial.rdox
2021-03-01 13:01:31.1515|INFO|Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsPresentationController|Loaded hotspots file C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\Default VT.xhs
2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction|Could not open session document
C:\\Users\\testuser\\Documents\\Micro Focus\\Reflection\\serial.rdox

2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction|Connection keyword is invalid for the current connection type
2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction| at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)
at Reflection2.Reflection2.ConnectionSetting(String Setting)
at Attachmate.TerminalServices.TSReflectionUO.SessionRUO.ConnectionSetting(String setting)
at Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsModel.OnDocumentViewOpened(DocumentView documentView, SettingsManager settingsManager)
at Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsPlugin.OnDocumentViewOpened(DocumentViewEventArgs e)
at Attachmate.Containers.Plugin.OnDocumentViewOpened(Object sender, DocumentViewEventArgs e)
at Attachmate.Documents.DocumentViewManagerEventHandler.Invoke(Object sender, DocumentViewEventArgs e)
at Attachmate.Documents.DocumentViewManager.Open(DocumentView documentView, ViewVisible viewVisible)
at Attachmate.Documents.DocumentViewManager.Open(Document document, ViewVisible viewVisible)
at Attachmate.Reflection.Core.Actions.OpenAction.OpenDocument(Uri uri, Boolean waitForStartupMacro, Boolean multiplexed)

2021-03-01 13:01:27.4958|INFO|Attachmate.Reflection.Core.ApplicationState|Loaded workspace window settings: C:\\Users\\stuartk\\AppData\\Roaming\\Micro Focus\\Reflection\\Desktop\\v16.2\\Frame.settings
2021-03-01 13:01:27.5460|INFO|Attachmate.Emulation.Frame.FrameApplication|Loaded default actions access settings
2021-03-01 13:01:27.8120|WARN|Attachmate.Reflection.Core.PCISettingsProvider|Failed to loaded PCI/DSS settings: C:\\Users\\stuartk\\AppData\\Roaming\\Micro Focus\\Reflection\\Desktop\\v16.2\\PCIDSS.settings
2021-03-01 13:01:27.8120|INFO|Attachmate.Reflection.Core.PCISettingsProvider|Loaded PCI/DSS settings: C:\\Program Files (x86)\\Micro Focus\\Reflection\\Configuration\\PCIDSS.settings
2021-03-01 13:01:27.9123|INFO|Attachmate.UIFramework.CustomUI.ActionResourcesManager|Reading action resources file: C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\CustomUI\\ActionResources
2021-03-01 13:01:29.1876|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects' as references
2021-03-01 13:01:29.1876|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'MSHTML' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'SHDOCVW' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Object library not registered
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects.Emulation.IbmHosts' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|[ApcDock] Init Failed to add 'Attachmate.Reflection.Objects.Emulation.OpenSystems' as references
2021-03-01 13:01:29.2033|ERROR|Attachmate.VBA.Engine.ApcDock|Name conflicts with existing module, project, or object library
2021-03-01 13:01:29.2827|INFO|MicroFocus.Utilities.CentralManagement.Legacy.Rsg.RsgSessionMgr|Attachmate.Emulation.Frame id 3544: RSG Session Manager is initializing.
2021-03-01 13:01:29.2827|INFO|Attachmate.Reflection.Core.Actions.OpenAction|Attachmate.Emulation.Frame id 3544: [[[[OP]]]] OpenAction OpenDocument Start 2355
2021-03-01 13:01:29.8307|INFO|Attachmate.Emulation.Frame.RibbonSessionUiHelper|Loaded UI file C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\CustomUI\\Reflection2007.VT.Ribbon.xuml
2021-03-01 13:01:30.8710|INFO|Attachmate.Services.InputCaptureService|End-of-input scan timeout is 60 milliseonds.
2021-03-01 13:01:30.9022|INFO|Attachmate.Plugins.Themes.ThemesPlugin|Applied theme C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Themes\\Classic\\Reflection2007.VT.themex to created document file:///C:/Users/stuartk/Documents/Micro Focus/Reflection/serial.rdox
2021-03-01 13:01:30.9335|INFO|Attachmate.Utilities.KeyboardMapper.KeyboardMap|Successfully loaded Keyboard Map: [C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\default VT.xkb]
2021-03-01 13:01:30.9335|INFO|Attachmate.Utilities.MouseMap.MouseMap|Successfully loaded Mouse Map: [C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\Default VT.xmm]
2021-03-01 13:01:31.0558|INFO|Attachmate.Utilities.ActionLogger|Executed action: DocumentViewOpened, parameters: file:///C:/Users/stuartk/Documents/Micro Focus/Reflection/serial.rdox
2021-03-01 13:01:31.1515|INFO|Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsPresentationController|Loaded hotspots file C:\\Program Files (x86)\\Micro Focus\\Reflection\\Built-Ins\\Keyboard Maps\\Default VT.xhs
2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction|Could not open session document
C:\\Users\\stuartk\\Documents\\Micro Focus\\Reflection\\serial.rdox

2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction|Connection keyword is invalid for the current connection type
2021-03-01 13:01:31.1717|ERROR|Attachmate.Reflection.Core.Actions.OpenAction| at System.RuntimeType.ForwardCallToInvokeMember(String memberName, BindingFlags flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)
at Reflection2.Reflection2.ConnectionSetting(String Setting)
at Attachmate.TerminalServices.TSReflectionUO.SessionRUO.ConnectionSetting(String setting)
at Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsModel.OnDocumentViewOpened(DocumentView documentView, SettingsManager settingsManager)
at Attachmate.Plugins.Emulation.OpenSystems.OpenSystemsPlugin.OnDocumentViewOpened(DocumentViewEventArgs e)
at Attachmate.Containers.Plugin.OnDocumentViewOpened(Object sender, DocumentViewEventArgs e)
at Attachmate.Documents.DocumentViewManagerEventHandler.Invoke(Object sender, DocumentViewEventArgs e)
at Attachmate.Documents.DocumentViewManager.Open(DocumentView documentView, ViewVisible viewVisible)
at Attachmate.Documents.DocumentViewManager.Open(Document document, ViewVisible viewVisible)
at Attachmate.Reflection.Core.Actions.OpenAction.OpenDocument(Uri uri, Boolean waitForStartupMacro, Boolean multiplexed)