Attempts to make changes to LonMaker drawing results in error message that write access is not available.
When the drawing is opened write access was not granted. By default write access is enabled, but it can be turned off when multiple users are accessing the same drawing file.
When opening the network ensure that the "Show all network options dialogs" checkbox is checked.
When you reach the Username prompt screen ensure that the "Write Access" field is checked and then complete opening the drawing.