Shrivelling Chillies

Change in environment probably. keep soil damp not wet. it looks like they're rotting on the branch. moving outside without hardening off won't have helped but it should adapt but may not be prolific in fruiting

 

If they're left on the plant chillies start to shrivel once they have reached full maturity. It could simply be just that. They need picking and eating . I'd prefer to look on the bright side and hope that they are just mature chillies.

That chilli in the front does look as though it may be starting to rot (as Loofah has said) so definitely remove it quickly. If it feels soft and a bit squiggy (technical word ) then throw it away. The rest don't look too bad but need harvesting.

From what I can see of the leaves, the plant doesn't look too stressed but having put it outside without hardening off wouldn't have helped it.