Repro:
var editor = new SyntaxEditor { Text = "Line1\nLine2\nLine3", IsIndicatorMarginVisible = true }; editor.Document.IndicatorManager.Bookmarks.Add (editor.Document.CurrentSnapshot.Lines[1]); editor.Document.Language = new SyntaxLanguage("test");var editor = new SyntaxEditor { Text = "Line1\nLine2\nLine3", IsIndicatorMarginVisible = true }; Editor.Document.IndicatorManager.Add<TestTagger, BookmarkIndicatorTag> (editor.Document.CurrentSnapshot.Lines [1], new BookmarkIndicatorTag());editor.Document.Language = new SyntaxLanguage("test");class TestTagger : IndicatorTaggerBase<BookmarkIndicatorTag> { public TestTagger (ICodeDocument doc) : base ( nameof (TestTagger), [new Ordering(TaggerKeys.Token, OrderPlacement.Before)], doc, false) { } }