ICAP Error

Does anyone know what following error means and how to fix !? Get it when trying to filter my list of posts 🙁

ICAP Error

An error occurred while performing an ICAP operation: Connection failure: Could not receive data due to dropped connection by the ICAP server.
There could be a network problem, the ICAP service may be misconfigured, or the ICAP server may have reported an error.

To escalate this issue, please contact your onsite IT support representative.