I am very sorry about sonmthing happened this afternoon, and it have been solved yet .

I am very sorry about something that happened this afternoon, and it has been solved yet .

你这个yet到底是想说解决了还是没解决，yet应该是没解决说的

something用法也不对
你可以说I'm sorry that something happened this afternoon,
也可以说I'm sorry about the things that(或三词换成WHAT) happened this afternoon.

sonmthing should be something

很有问题， 很难听到作者想要表达什么.