weight orders

edit

I found that installed Sage on my VM Ubuntu can't create weighted TermOrders. Using 'Force = True' results in a ring with just lex order. Reinstalling doesn't help.

Copying from http://sagemath.org/doc/reference/sag... results in Error massage: "verbose 0 (388: term_order.py, __init__) Term ordering 'wdegrevlex' unknown"

how can i fix that problem?