I was brought to attention regarding that matter, but I personally had thought that it was no problem.
ご質問ありがとうございます。
"I was brought to attention regarding that matter,"=「私はその案件について注意されました。」
(☆"bring someone's attention to something"=「誰々に~について指摘する」)
"but I personally had thought that it was no problem."=「ただ、個人的にはそれは問題ないと私は思ったのです。」
ご参考に。