Curse of Strahd not showing Haunted One's Background

as stated in title, new players started to create a haunted one but were left to hard copy.  Monster hunter pack is missing from the compendium.

I've got the same issue. ( To clarify for those who don't know; these options are presented under Appendix A of that module. ) However the character background for 'Haunted One' does start off by saying; " During character creation, players can select the following background for their characters, with your approval. It is appropriate for any character or campaign associated with eeriness or horror. " So my guess is they left this option out of the charactermancer for those DM's who don't approve. I've also noticed the Monster hunter pack for that background missing from the compendium for easy drag&drop ( for the same reason I guess ), however Appendix A does mention the cost and items included in the pack.

According to a post on this about a year ago by Loren the GM: 'Older modules were created before the Charactermancer and don't include support for it. Devs have mentioned adding this to older modules, but have not ever given a timeline or definitive answer on doing so. Your best option is to do it manually. You can share the background info through a handout and let your player input it, or you can add it to the sheet as the DM.' Hope this helps.

Iceking has the right of it. Modules, Charactermancer and the Compendium kind of grew up together. Older modules do no yet have all Compendium and Charactermancer features. The Background might be draggable onto a character sheet, but you will need to do some adjustment manually. This should not affect Charactermancer LevelUp, which is actually a different batch of code and doesn't care about backgrounds.