I've your using either Xero, FreeAgent, SageOne, KashFlow or Quickbooks Online then it is possible that your 'Token' will expire.
A token is like a password Commusoft uses to securely talk to the accounting system. In some circumstances this token can expire (this means your accounting package is no longer accepting it). If this happens, please go to:
Your Business > Company Details > Integrations > Advanced options > Reconnect Token
This will take you to your accounting package login page (if you're not logged in) or a secure page where you will need to confirm you're happy for Commusoft to link to your accounting package. Please accept this.
Once you've done that Commusoft will try to resend all the queued up information that hasn't been sent.