There is a dialogue box that warns about previously created temporary files and ask me whether I want to delete them. There is a long and detailed description, which is a good thing. However, if I have encountered this warning box in the past, I already know what it is about. But I still have to scan the complete description to find out what the "Yes" and "No" buttons do: is the question "Do you want to delete these file?" or "Do you want to keep these files?".
I suggest keeping the long description unchanged, but also displaying the main question separately (as a heading, in bold font), or alternatively displaying it in the title bar of the window (which only says "Warning" at the moment).
This would improve usability, as the user will not need to read the long description to find out what the Yes/No buttons do.