There is something, maybe even just a space, entered in a cell on the bottom row, so you cannot insert any more rows.
You could press Ctrl+DownArrow and see what is there, or, delete that last row if you can’t see anything important.
Of course, if you have filled a formula all the way down a column to the very end, then you are using all the rows
1 Like
I closed the file while waiting a response and now I’ve opened it again the message is gone. I tried your suggestion and there appears to be nothing from 26000 to the end. just one of those things I suppose. thanks for the prompt assistance.