The title is not very precise, so here is the recipe.
1. Have a formerly saved document open. Do some changes to the document, so that the document tab shows [Modified].
2. Switch e.g. to Preferences > Performance and turn on / off Hardware Acceleration and click Yes for restart.
3. You get a warning that there is an unsaved document. Click Yes to save.
Result: Application closes, but it is not restarting.