Cannot open graph .gcx file saved by Grapher I'm facing an issue where I am unable to re-open any saved graphs that have a contour plot inside. For example, if you plot sin(x)*cos(y) and save it, you will not be able to reopen it in Grapher. It will just say: The document “test.gcx” could not be opened.   

Example of a plot that I cannot save and re-open:
Apple's grapher does not save and reopen correctly files without real equation (with the sign equal)
Another problem is with upgrading the os, and the security : sometimes you have to allow (with &quot;open anyway&quot; box in the security preference panel) the system to load a file previously created.