To delete elements from the project, you may choose to either:
Input workbook edits, especially manual edits, require a model refresh to update the graphical representation of the model in the model workspace, while graphical editing will dynamically update the model, for example when adding framing elements (or deleting elements) using the modelling interface.
When using the model toolbar tools to select elements, press the escape key after editing is completed to deselect all elements (if applicable) and finish all editing commands that may still be active.
The '+' cursor icon in the model workspace indicates that an edit command is active, while the default mouse pointer icon indicates that no commands are actively running or waiting for input.