chillis slightly going yellow only produced one fruit i took it off when ripe its still flowing but the flowers are dropping and not producing any more fruit
If I had to venture a guess, you've got a pollination problem due to lack of air flow and pollinators. That would lead it to produce flowers that drop off. Increasing air flow is as easy as adding a fan to run a few times a day. Adding pollinators might not be reasonable since it looks to be an indoor plant. My old fall-back is to hand pollinate with a small watercolor brush. Just brush each flower every couple of days, spreading the love. It'll do wonders.
The yellowing could be a number of things that I'm not qualified to diagnose.