While linking bank account of client, a message of failure of validation is appeared due to technical issue. Income tax department says it is on bank end ,on other hand bank says pan is updated there is no issue at there end.
You have net banking in this account..? If you have than Login to bank with net banking, and Go to income tax login from net banking.. it's automatically got validated..
Download Pdf from this link...I think it will help you.. https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.incometaxindiaefiling.gov.in/itax/mail_images/Link_Your_PAN_and_Bank/PAN-Bank_Account.pdf&ved=2ahUKEwii1uCJsMjrAhWa93MBHaDgDnoQFjADegQIARAB&usg=AOvVaw2i0-4DtmJ2RX7dSFwMBxuk