A circular dependency detected

Hi Guys,

I'm very new to PowerBI and in my previous post i want to calculate a SLA score for my telephone. Now i made 4 colums:

AcceptedQueuetime = calculate(countrows(PowerBI_Customer_Last180Days); PowerBI_Customer_Last180Days[queuetime]<20)

Missed = sum (PowerBI_Customer_Last180Days[MissedCalls])

Accepted = sum (PowerBI_Customer_Last180Days[AcceptedCalls])

SLA = DIVIDE(PowerBI_Customer_Last180Days[AcceptedQueuetime];(PowerBI_Customer_Last180Days[Accepted]+PowerBI_Customer_Last180Days[Missed]))

Here is my table with columns:

But when i click the SLA column i get the message:

A circular dependency detected: PowerBI_Customer_Last180Days[AcceptedQueuetime]; PowerBI_Customer_Last180Days[SLA]+PowerBI_Customer_Last180Days[AcceptedQueuetime]

What is wrong with the calculation i'll hope someone can help me