Child Table Attach field Permission Isssue

I Created A doctype Name Query wich Have a Child Table containing Fields “documents”, type link
“issue_date”, date
“expiry_date”, date
"attachment , while a user save document with attachments, its getting Error for Permissions, but with Attachment Sav is working fine and saving , aftre save client can upload attachment in draft mode , , aftre save client will submit (custom workflow action submit ==0 ) but im facing issue wile attach from client role and save i m getting error for this user not have permission to create new (random name) any sulotion for this , this hapning only while attach file with out attachment it is working fine