problem with update

[nacer]

Hi,
I'm new freerunner user. I'm running shr but I'm experiencing two issues 
with that os:
- my gps system seems to not working. When I launch tangogps I still 
have a "no gps found". Looking the logs, the system is looking for pwron 
file that doesn't exist.
- Then I thought an upgrade of the system would be a solution. But when 
I try the update, the Xserver stop functionning and I'm not able to make 
it works again.
Can you help me please?