[fixes] raise exception while deleting fiscal year if fiscal year is set as default in Global Settings and while calculating get_month_details if year_start_date not found
diff --git a/erpnext/accounts/doctype/fiscal_year/fiscal_year.py b/erpnext/accounts/doctype/fiscal_year/fiscal_year.py
index 9456924..8ff209a 100644
--- a/erpnext/accounts/doctype/fiscal_year/fiscal_year.py
+++ b/erpnext/accounts/doctype/fiscal_year/fiscal_year.py
@@ -40,6 +40,11 @@
 
 	def on_update(self):
 		check_duplicate_fiscal_year(self)
+	
+	def on_trash(self):
+		global_defaults = frappe.get_doc("Global Defaults")
+		if global_defaults.current_fiscal_year == self.name:
+			frappe.throw(_("You cannot delete Fiscal Year {0}. Fiscal Year {0} is set as default in Global Settings").format(self.name))
 
 @frappe.whitelist()
 def check_duplicate_fiscal_year(doc):
diff --git a/erpnext/hr/doctype/process_payroll/process_payroll.py b/erpnext/hr/doctype/process_payroll/process_payroll.py
index a71200c..51e3740 100644
--- a/erpnext/hr/doctype/process_payroll/process_payroll.py
+++ b/erpnext/hr/doctype/process_payroll/process_payroll.py
@@ -206,3 +206,5 @@
 			'month_end_date': med,
 			'month_days': month_days
 		})
+	else:
+		frappe.throw(_("Fiscal Year {0} not found").format(year))
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