Submit then quickly delete.
Can't delet unsubmitted post
Submit then quickly delete.
I thought about it, so I wrote as subject explicitely: "can't delete unsubmitted post" 
The "official" way with this delete-button is not working anyway?
Is any "owner" (or moderator) of this site knowing about it (and correcting this bug)?
Nevertheless thanks for your answers. I have deleted my test-editings by this way and will take care in the future not creating such thing again.

Hi,
I've created a new post and pushed the butteon "save & preview".
Than above this post I have the well known three buttons: "Delete", "Edit" and "Submit >>".
The last to are working, but I can't delete (!!!) this unsubmitted post.
When trying to delete, I always get this message:
Oops?! Invalid server request!
It appears you are passing some invalid parameters in your request. Please try again or contact us if you feel this was our fault.
I have deleted the cash of the browser (restarted it) and even tried a different one, but deleting is not possible.
Any help?
Thanks,
Bernhard