When I copy worksheets with locked cells into another workbook, cells on the first worksheet are not editable even though they aren't locked. The error message refers to a different worksheet where that particular cell is protected (ie. cell A1 on sheet one is not locked on sheet one but is locked on sheeet A2). If I go to another worksheet then come back to the first sheet in Excel, I no longer get the error message and the cells are editable.
I've attached example code exhibiting the issue. For the example to work, you have to use an Aspose.Cells.lic file, otherwise the worksheet will open to the "Evaluation" worksheet and you won't see the issue on the first worksheet. The output worksheet protectionissue.xlsx illustrates the issue. I also included a screenshot of the error message in screencapture.png.