I'm getting the following error when I'm doing merge replication. Plz, tell me how can I overcome this problem. I cannot able to start the agent... Plz, someone help me

Login failed for user 'myserver\login name'. Reason: Token-based server access validation failed with an infrastructure error. Check for previous errors. [CLIENT: ]

Error :18456,Severity :14,State:11 in the error log...

Atleast any troubleshoot...