If you do not have "write permissions" for the selected Family Tree, it will be opened in a Read Only mode. In this mode, the data may be viewed, but no changes will be made to the Tree. To indicate this mode, the title of the main window will be appended with '''(Read Only)''' text.

GRAMPS allows you to open certain databases that have not been saved in GRAMPS' own file format from the command line, see [[Gramps_3.1_Wiki_Manual_-_Command_Line#Opening_options|Command line references]]. These include XML and GEDCOM databases. But you should be aware that if the XML or GEDCOM database is relatively large, you will encounter performance problems, and in the event of a crash your data can be corrupted. Hence, it is normally better to create a new GRAMPS family tree (database) and import your XML/GEDCOM data into it.