Can you post the E-Nr number of the appliance please?
It should be on a label in the door recess.
F16 is shown as a door lock problem.
The machine is reporting it's unable to lock the door.
Close the door a little harder than normal.
Once closed give the door a good push/ slight thump on the handle.
Try it again.
If you are lucky, it's just a sticky switch and this will free it off.
If not, you'll need to check the door latch on the door, ensure it's being fully pushed over by the spring.
If ok, you'll need to try a new door lock.
Try it out, see what happens.
hope this helps
Let me know how it goes or if you need more help
Did the machine lock?
Have you tried it again since slamming it?
As previous, Have you tried the machine again since you slammed the door?
It may be working normally now, as previous, I advised that it may just have been a sticky switch.
If it only works by slamming, carry out the checks on the latch pin that I previously advised.
Then, if all is ok, change the door lock.
Let me know how it goes.