[MCPE-172779] [ScriptAPI] applyDamage -> Player is not valid type in interface EntityApplyDamageOptions

You can't specify player as source of damage when applyDamage method is used on entities.
Code to reproduce:

anyEntity.applyDamage(5,{damagingEntity:mustBePlayer});

anyEntity.applyDamage(5,{damagingEntity:mustBePlayer});

Error message:

[media]

Pack to reproduce available: down below

Attachments

Luckily this is not a bug, you are just missing the non-optional damage cause. e.g.

anyEntity.applyDamage(5, { cause: "magic", damagingEntity: mustBePlayer });

anyEntity.applyDamage(5, { cause: "magic", damagingEntity: mustBePlayer });