Circular reference issue at EXcel

Hi,
I always bump into below issue please help me resolve.

Microsoft Office Excel
Circular Reference Warning
One or more formulas contain a circular reference and may not calculate correctly. Circular references are.
For example, a cell that refers to its own value or a cell that refers to another cell which depends on the or
For more information about understanding, finding, and removing circular references, click OK. If you want
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