When we cancel the sales invoice it give an error "ImportError: Module import failed for POS Closing Voucher"

[Laxman_Singh]

When we cancel the sales invoice then it gives below error:

ImportError: Module import failed for POS Closing Voucher (erpnext.selling.doctype.pos_closing_voucher.pos_closing_voucher Error: No module named ‘erpnext.selling.doctype.pos_closing_voucher.pos_closing_voucher’)

Kindly help.