Iam trying to build a StatusLog, every move that happens on application. For example, the user clicked in the button1, the progressBox must receive a string like \"user cli
Try insertPlainText() instead. The documentation does not mention insertText so the error is quite descriptive.
insertPlainText()
insertText
You'd need to use the .appendPlainText(text) function to do it. Here's the documentation for it.
.appendPlainText(text)