Question

i'd love to remind you that this problem is very co mmon and

Answer 1

I'd love to remind you这是主句.I是主语, would love to remind谓语, you是宾语.

两个that引导的都是宾语从句的内容,是并列成分.第一个that可省,第二个不可省.

this problem是第一个宾语从句的主语,is是谓语,common是表语.

you是第二个宾语从句的主语,don't need to worry about是谓语,助动词加行为动词的用法（因为这里是否定,所以用need的助动词形式）that就是宾语了.