Digital signature

Dear Sir,

While I was uploading a client company's form 66 it is showing an error message (Signature Validation failed for signature field for Director / Manager / Managing Director / Secretary. The person is not authorised to sign on this filed.) but the singatory is the Director of the Company and having valid DIN Number and is Registered with DSC till 2012. 

Please give me some information how to upload in MCA website.

Thanks & Regards

Ajith