Blueprint warning: what does Object 'Something__DelegateSignature' isn't imported, because its outer is a placeholder mean?

I have been having this issue for some time now. I have a delegate on a blueprint (say a character) than other classes (spell actors) then subscribe to to act on additional events. For example, a link spell will subscribe to OnHealthChange delegate on a player to also apply the damage on the linked player.

Everything seems to work but I am receiving this (annoying) Object ‘OnHealthChange__DelegateSignature’ isn’t imported, because its outer is a placeholder. Am I using the blueprint delegates in a wrong way, should I be concerned? This warning appears on loading the editor, packaging the game and also when running the game in the log and I would like to get rid of it. Does anyone have any ideas what could I be doing wrong?

Thanks for reply in advance

Therefore warning is a temporary measure to avoid the error , you do not have to worry about .It will be removed at 4.8 .