Aggressive cleaning agents have been used or the door seal has been subjected to excessive stress.
Replace the damaged door seal with a new one.
The oven door seal is cracked or damaged.
Replace the damaged door seal with a new one.
Replace the damaged door seal with a new one.
For this reason, it is best to clean the seal every time the oven is used using a clean sponge cloth and a solution of warm water and washing-up liquid, or a damp microfibre cloth. Wipe the seal dry using a soft cloth.