Invalid Session ID found in SessionHeader: Illegal Session

[Hitha]

Hello - I am facing this error 'Unable to connect to Salesforce because of an invalid session ID'. I am not sure how to restore the Marketo and SF connection. None of the new leads/changes are syncing to SF.

[SanfordWhiteman]

Do you have another app sharing the same SFDC API credentials?

[Hitha]

No, we don't have another app sharing the same credentials? Do you mean the OAuth consumer key and secret?

[ktronolone]

This happens to us about every 4 months in our sandbox instance and is typically resolved by resetting the sfdc credentials for the Marketo sync user.