sorry for the confusing post.
i have a font with eg the glyph radical. I copy it from the font collection and do File –> New font. Then with no glyph selected in the new font I press paste. I can see the radical in the font collection. I select it and open a space center window. The radical is shown in the “input bar” but not in the actual window. Also in the metrics i can see the radical but no values for width, left and right margin.
if i close the font and then reopen it everything is fine.
Sorry again and thanks for the quick reply.