Getting error messgae when trying to change in Detected in Cycle. Using the replace option.

We are trying to change the Detected in Cycle from "X" to "Y" and are receiving an error message saying "X" not found. But actually the value "X" is existing. We are using replace option.We are gettign this error when trying to search for any value using replace option.

Could any one please help with this error.

Thanks

Sailaja