Comment 4 for bug 1425612

Stranger and stranger.
I've looked at it again and I'm still seeing it in 1.6.0.160

Clearly there was some intermediate step that I didn't realise was making a difference. This time I was able to reproduce this repeatedly.

This time I opened an image, hit the duplicate layer button, then closed the image without saving.

The menu items are not disabled and cause the exceptions.