When trying to open the System Monitor, I received an error saying that the files
SystemLoad2.sgrd contain malformed XML. The resource graphs no longer appeared after the program loaded.
How can I fix that?
Go to the folder...
I created a folder and moved the two files in to it in case it caused even worse problems. When I started System Monitor the graphs showed up again.
Apparently files in your own home directory are safe to delete if you did not create them.