Maintain elements: MenuType &2 for Presentation &1 is invalid.
&1 - Surrogate for the presentation
&2 - The invalid menu type
This is an internal error. Contact Websydian Support.
This can happen if you define a new presentation for the "Maintain Elements" process from the administration interface. You should never need to do this.
If it is absolutely necessary - contact Websydian Support to obtain information about how to make it work.