[fix] Return account currency only if account provided
diff --git a/erpnext/accounts/doctype/account/account.py b/erpnext/accounts/doctype/account/account.py
index 7b6d0da..c3e4c39 100644
--- a/erpnext/accounts/doctype/account/account.py
+++ b/erpnext/accounts/doctype/account/account.py
@@ -210,6 +210,8 @@
 
 def get_account_currency(account):
 	"""Helper function to get account currency"""
+	if not account:
+		return
 	def generator():
 		account_currency, company = frappe.db.get_value("Account", account, ["account_currency", "company"])
 		if not account_currency: