As you are building your data flow, remember to save your work occasionally. To save your data flow, click the Save button on the toolbar.
If this is the first time you are saving your data flow you will be prompted to enter a name. Enter a unique name (that you haven't already used before in your My Documents folder) and hit Save. Every time you hit Save from that point on, your data flow will simply be updated with the latest changes.
If you want to save a data flow that has already been saved with a different name, you can select Save As from the toolbar menu button.
If you click the Exit to Directory button without saving your latest changes you will be prompted to save. You will also be asked whether you wish to lose your unsaved changes if you close the browser tab.
However, if you close the browser, or the browser crashes, the system will not have an opportunity to prompt you to save your changes. To avoid the loss of work, the application always keeps a backup copy of your data flow, which will have your latest changes saved. If you do not save your data flow before closing the browser, then the next time you open it, you will be asked if you wish to carry on working on the backup copy (which contains your very latest changes), or whether you wish to continue working on your last saved version.
In most cases you will want to Restore Latest Backup and continue working on the version which includes your latest changes. You will only want to choose Open Last Saved Version if you were experimenting with throw away changes before you closed down your browser.