After updating to 9.2.0016 many problems showed up.
One of them is that advanced search form does not show up. I one grid yes, in an other no. How come?
My reaction was, oh than I have made a mistake somewhere in that grid where it did not show up.
After many hours searching I made a complete new grid. No results. Shit what to do.
The big trick is to rename the grid concerned and change it also in the menu app of course. Problem solved.
So there must be something in the Menu app.