GRAVE: Error while logging in on the engine API.

Hello, the following error

GRAVE: Error while logging in on the engine API.

appears in the log when I run my process. Someone can tell me to do and how to fix it?

Hi, this is the full message that appears when I start a task

26/05/2014 09:44:50 org.bonitasoft.console.common.server.login.datastore.LoginDatastore login
GRAVE: Error while logging in on the engine API.

Hi,
Can you provide us with more logs, to help you track down the problem?
Thx and regards
Emmanuel