In some rare cases the unsent check makes a mistake. Can't tell the
exact circumstances, but if you see it right after a send and receive,
then do not worry...
After a Receive is complete ArchiCAD has to refresh the project, do some
maintenance on it. Sometimes it modifies/updates information, which seem
to be a Change, so it claims there are unsent changes. Sometimes a send
fixes it after S&R, but there ar...