emcli import_update error

I've install OEM12C with BP1 on a Linux VM , and need to monitor the DB on AIX server.

I downloaded the agent software for AIX,and use emcli to import to the EM software library,but failed.

Here's the steps:

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[oracle@oem12c ~]$emcli login -username=sysman
Enter password :

Login successful
[oracle@oem12c ~]$ emcli import_update -file='/tmp/12.1.0.1.0_AgentSoftware_212.sar' -omslocal
Error: Session expired. Run emcli login to establish a session.
[oracle@oem12c ~]$ emcli synchronize
Error: the command name "synchronize" is not a recognized command.
Run the help command for a list of recognized commands.