Exception: 'frappe.exceptions.PermissionError'

In lead doctype admin user is uploading file but he is facing error even it has permission to read and write for particular document , can anyone help , how to solve this.

{exception: 'frappe.exceptions.PermissionError', exc_type: 'PermissionError', exc: '["Traceback (most recent call last):\\n  File \\"app…ssionError\\nfrappe.exceptions.PermissionError\\n"]', _server_messages: '["{\\"message\\": \\"Not allowed via controller permi…", "{\\"message\\": \\"\\", \\"title\\": \\"Message\\"}"]', _error_message: 'Insufficient Permission for File (<strong>write</strong>)', …}
exc
: 
"[\"Traceback (most recent call last):\\n  File \\\"apps/frappe/frappe/app.py\\\", line 110, in application\\n    response = frappe.api.handle(request)\\n  File \\\"apps/frappe/frappe/api/__init__.py\\\", line 49, in handle\\n    data = endpoint(**arguments)\\n  File \\\"apps/frappe/frappe/api/v1.py\\\", line 53, in update_doc\\n    doc.save()\\n  File \\\"apps/frappe/frappe/model/document.py\\\", line 337, in save\\n    return self._save(*args, **kwargs)\\n  File \\\"apps/frappe/frappe/model/document.py\\\", line 363, in _save\\n    self.check_permission(\\\"write\\\", \\\"save\\\")\\n  File \\\"apps/frappe/frappe/model/document.py\\\", line 220, in check_permission\\n    self.raise_no_permission_to(permtype)\\n  File \\\"apps/frappe/frappe/model/document.py\\\", line 241, in raise_no_permission_to\\n    raise frappe.PermissionError\\nfrappe.exceptions.PermissionError\\n\"]"
exc_type
: 
"PermissionError"
exception
: 
"frappe.exceptions.PermissionError"
httpStatus
: 
403
httpStatusText
: 
"FORBIDDEN"
message
: 
"There was an error while updating the document."
_error_message
: 
"Insufficient Permission for File (<strong>write</strong>)"
_server_messages
: 
"[\"{\\\"message\\\": \\\"Not allowed via controller permission check<br>User <strong>info@solarblocks.us</strong> does not have access to this document: User - Administrator\\\", \\\"title\\\": \\\"Message\\\"}\", \"{\\\"message\\\": \\\"\\\", \\\"title\\\": \\\"Message\\\"}\"]"
[[Prototype]]
: 
Object