Sorry, it's hard for me to reproduce this error, because it appears randomly and has a certain probability.
Just now, I found a similar error:
System.NullReferenceException
HResult=0x80004003
Message=object reference is not set to an instance of the object.
Source=ActiproSoftware.Text.Addons.DotNet.WinForms
StackTrace:
At ActiproSoftware.Internal.HB.EI3(EwS , ITypeDefinition , TypeMemberDeclaration )
At ActiproSoftware.Internal.HB.TdH(dT , ITypeDefinition , MethodDeclaration )
At ActiproSoftware.Internal.HB.QI7(ITypeDefinition , MethodDeclaration )
At ActiproSoftware.Internal.Rn.kiy(L4 , IAstNode )
At ActiproSoftware.Internal.Rn.Jif(L4 , IAstNode )
At ActiproSoftware.Internal.Rn.DbE(L4 , IAstNode , VariableDeclarator , String , Expression , Boolean )
At ActiproSoftware.Internal.Rn.rbi(L4 , IAstNode , IAstNode , Nullable`1 , String )
At ActiproSoftware.Internal.Rn.bic(L4 , ISimpleName )
At ActiproSoftware.Internal.Rn.Mb0(L4 , ISimpleName )
At ActiproSoftware.Internal.Rn.kb5(L4 , ISimpleName )
At ActiproSoftware.Internal.Rn.kb1(L4 , Expression )
At ActiproSoftware.Internal.Rn.Hba(L4 , MemberAccess )
At ActiproSoftware.Internal.Rn.kb1(L4 , Expression )
At ActiproSoftware.Internal.Rn.Ibo(L4 , InvocationExpression )
At ActiproSoftware.Internal.Rn.kb1(L4 , Expression )
At ActiproSoftware.Internal.Rn.Resolve(IResolverRequest )
At ActiproSoftware.Internal.nwQ.Resolve()
At ActiproSoftware.Text.Languages.VB.Implementation.VBParameterInfoProvider.RequestSession(IEditorView view)
At ActiproSoftware.Text.Languages.DotNet.Implementation.DotNetParameterInfoProviderBase.TQb(IEditorView , Boolean )
At ActiproSoftware.Text.Languages.VB.Implementation.VBParameterInfoProvider.OnDocumentTextChanged(SyntaxEditor editor, EditorSnapshotChangedEventArgs e)
At ActiproSoftware.Text.Languages.VB.Implementation.VBParameterInfoProvider.ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.IEditorDocumentTextChangeEventSink.NotifyDocumentTextChanged(SyntaxEditor editor, EditorSnapshotChangedEventArgs e)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.OnDocumentTextChanged(EditorSnapshotChangedEventArgs e)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.CAp(EditorSnapshotChangedEventArgs )
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.JAe(TextSnapshotChangedEventArgs )
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.KAc(Object , TextSnapshotChangedEventArgs )
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.<>c.dSz(SyntaxEditor instance, Object source, TextSnapshotChangedEventArgs eventArgs)
At ActiproSoftware.Text.Utility.WeakEventListener`2.OnEvent(Object source, TEventArgs eventArgs)
At ActiproSoftware.Text.Implementation.TextDocumentBase.OnTextChanged(TextSnapshotChangedEventArgs e)
At ActiproSoftware.Text.Implementation.CodeDocument.OnTextChanged(TextSnapshotChangedEventArgs e)
At ActiproSoftware.Text.Implementation.TextDocumentBase.cfQ(Wd , Action`1 )
At ActiproSoftware.Internal.Wd.Apply()
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.Primitives.EditorView.ReplaceSelectedText(ITextChangeType type, String text, IEditorViewTextChangeOptions options)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.EditActions.TypingAction.Execute(IEditorView view)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.Primitives.EditorView.ExecuteEditAction(IEditAction action)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.Primitives.EditorView.PerformTyping(String text)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.Primitives.EditorView.m8v(TextCompositionEventArgs )
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.W5D(IEditorView , Keys , Char )
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.OnKeyPress(KeyPressEventArgs e)
At System.Windows.Forms.Control.ProcessKeyEventArgs(Message& m)
At System.Windows.Forms.Control.ProcessKeyMessage(Message& m)
At System.Windows.Forms.Control.WmKeyChar(Message& m)
At System.Windows.Forms.Control.WndProc(Message& m)
At System.Windows.Forms.ScrollableControl.WndProc(Message& m)
At ActiproSoftware.UI.WinForms.Controls.SyntaxEditor.SyntaxEditor.WndProc(Message& m)
At System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
At System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
At System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
At System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
At System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
At System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
At System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
At System.Windows.Forms.Application.Run(Form mainForm)
....
I guess some your codes are not rigorous enough to judge whether an object is null.
The "actiprosoftware. Internal. Hb. EI3" method failed both times. Please check the code of this method carefully
ActiproSoftware.Internal.HB.EI3(EwS , ITypeDefinition , TypeMemberDeclaration )