Getting SFDC and Marketo Sync Error - "This error usually occurs after a session expires or a user logs out"

[EricDeinoff]

Hi, my Marketo program and SFDC campaign sync seems to have stopped working. I tried to troubleshoot by "adding to SFDC campaign" in the person record. I am getting this error message. Curious as to whether anyone can explain how to fix?

Sfdc Lead insert failed: "Invalid" Session ID found in SessionHeader: "Illegal" Session. Session not found, missing session hash: jEDVYEOJh9XYi1fB0PtE49BqvD0x91Dz20i0L2FyPGQ= This error usually occurs after a session expires or a user logs out. Decoder: DataInDbSessionKeyDecoder

[Vinay_Kumar]

@EricDeinoff 

Could you please confirm if you are using a separate integration user for Marketo Salesforce sync or are you using a shared user?

Is there any password expiry limit for the integration user?

Also, is there any session limit added in session settings?