In these cases this Vocas lens mount adapter support can be used. The Vocas lens mount adapter support works with any lens mount adapter that has a 1/4″ connection on the underside, and prevents damages to the lens mount of the camera especially when using heavy lenses.
Vocas 15mm lens mount adapter support
€175.50 ex vat.
Lens mount adapters from other brands such as Metabones sometimes require a support in order to not strain the lens mount of the camera to much.