Mcebuddy runs as a local service and not as a local user. There is no way for it to use the same credentials as the local user mapped drives since they are different logins. It's a windows limitation.
There are 2 ways out of this. Open the service manager and change the mcebuddy service run as user from local service to the local user. If the local user does not have admin privileges it will create a problem.
Simpler would be just to add the same credentials you are using for your mapped drives to mcebuddy. That way there is no conflict and everything works.
Where have you uploaded your log?