When I first downloaded and installed Sage (several versions ago) to try it out on Ubuntu, everything worked without error. I didn't do much with it, time passed, and when I came back to Sage, I saw 4.6 was there. I completely erased the folder that Sage was in, downloaded and untarred 4.6, and ran Sage. That's fine--commands input in the terminal work fine. But when I try to run notebook(), I get
UnpicklingError Traceback (most recent call last)
/home/me/.sage/<ipython console=""> in <module>()
/home/me/Math/sage46/devel/sagenb/sagenb/notebook/notebook_object.pyc in __call__(self, args, *kwds)
215 """
216 def __call__(self, args, *kwds):
--> 217 return self.notebook(args, *kwds)
218
219 notebook = run_notebook.notebook_twisted
.
.
.
UnpicklingError: invalid load key, 'n'.
I know how to spell Python, but not much more. Any idea what got messed up and suggestions on how to fix it?