You may be logged out of Swift911 for security if the window is left unattended for too long. If you made changes to a map and left the window open for a period of time without saving, you may encounter an error when attempting to save.
For this reason it is a good idea to save continuously when editing a map shape.
If you encounter an error when saving a map shape, keep the window open, and open a second tab in the browser for Swift911. This will mean having two tabs side by side. You will need to make the changes again in the new tab, but keeping the first tab open will allow you to use it as a reference.
Make the changes and save in the new tab.