Hi, I am experiencing the same issue in Ventura 13.4. I want to change the Calculator default icon and even with SIP or SSV protection lifted, the system won't let me. For some other apps and folders, I customized icons without any issues. I notice, you posted your question 3 months ago this moment, and not a single response? I wonder if its a hidden defect and its so well hidden that no one has seen it yet. Or this is so-o-o difficult to resolve that no one knows where to begin? I have read similar posts elsewhere on Internet. Which means there are others looking for a working resolution. It would be much appreciated of someone from a development team explained in detail how to achieve this. Thanks, Andrew