How to repair ceiling wall joins?

[RP66]

I have just moved into a new home [not newly built] and the tape between ceiling and plaster board-walls is coming unstuck showing horrible cracks etc.
What is the easiest way to repair these, the ceiling is artexed.
Thanks.

 

[23vc]

Got a pic? Scrim tape wouldn’t normally come unstuck, as it’s buried in plaster. Might wanna check possible causes ie movement between wall and ceiling before repairing

 

[RP66]

Thanks for reply.
Pictures below, hope they are clear enough.

 

[23vc]

I think that’s the paper tape they use for tape and joint rather than skimming, you may be able to just stick it back down.