Sometimes when you create tables to send to other users you do not want the users to be able to modify the IVT files.
You can lock the IVT files so that they cannot do this.
To lock an IVT file, select Lock from the File menu. This sets a table to read-only mode.
Sometimes when you open a table the window title indicates that the table is read-only:
This can show as Read-only even when the file attributes are not read-only:
When the table shows as Read-only and the file attributes are not set to read-only, this means that the table is locked.
To unlock the table, select Lock from the File menu. This allows you to write to the table.