Hello Robin.

How to solve the error message as this title while only one user use the data. It's strange that when I try to skip from new row in grid(the addnew property set to true), the error message popout and even ignore the error, I still couldn't edit the new record in the grid.

You need to set focus off the grid to a different object on the form before you issue commands like REPLACE on the grid's RecordSource.