Fixed patch

frappe/patches/v7_0/update_report_builder_json.py

@@ -6,7 +6,7 @@ import frappe
 
 def execute():
 	for report in frappe.db.sql_list(""" select name from `tabReport` where report_type = 'Report Builder'
-		and is_standard = 'No'"""):
+		and is_standard = 'No' and `json` != '' and `json` is not null """):
 		doc = frappe.get_doc("Report", report)
 		doc.update_report_json()
 		doc.db_set("json", doc.json, update_modified=False)