Senior Sims stuck moving on

Hi,

Some of my senior Sims have reached the end of their life span but can't move on.

They have a pool of light at their feet, an exclamation mark above their heads and can no longer participate in any activity but when the 'cycle of life' box appears and I click on 'yes' to move my Sim onto the next phase of their life (afterlife) the Grimm doesn't appear and the exclamation mark comes back.

This started about a week ago and I saw a lot of other people were having the same issue so assumed there would be an update and it would be resolved pretty quickly.

I now have 13/31 Sims stuck in this limbo status and I can't add any new Sims to replace them so I no longer have any toddlers etc to use for challenges.

Please advise.