Electronic reporting (GER) format designer allows to manage a custom electronic document’s format by specifying the desire layout and adding required datasources. The error 'The expected type was int, but the encountered type was str.' occurs when a new blank format is opened in GER designer for editing and a new child item is added to the entered root item of the designing format. After this, the entered child item can’t be selected for further editing.
To work around this issue, you may save changes, close GER designer form and open in GER designer this format again.