params validate occurs Error:

[{"message":"\"cid\" length must be less than or equal to 30 characters long","path":["cid"],"type":"string.max","context":{"limit":30,"value":"310821\\\"+target=\\\"_blank\\\"+rel=\\\"\\\"+style=\\\"text-decoration:+none;+color:+rgb(128,+128,+128);+vertical-align:+middle;\\\"+target=\\\"_blank","key":"cid","label":"cid"}}]