diff --git a/erpnext/support/doctype/service_level_agreement/service_level_agreement.js b/erpnext/support/doctype/service_level_agreement/service_level_agreement.js
index bfbffe2..4dbb0e7 100644
--- a/erpnext/support/doctype/service_level_agreement/service_level_agreement.js
+++ b/erpnext/support/doctype/service_level_agreement/service_level_agreement.js
@@ -111,6 +111,7 @@
 				filters: [
 					['DocType', 'issingle', '=', 0],
 					['DocType', 'istable', '=', 0],
+					['DocType', 'is_submittable', '=', 0],
 					['DocType', 'name', 'not in', invalid_doctypes],
 					['DocType', 'module', 'not in', ["Email", "Core", "Custom", "Event Streaming", "Social", "Data Migration", "Geo", "Desk"]]
 				]
diff --git a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
index ea617fd..de8f506 100644
--- a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
+++ b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
@@ -29,6 +29,7 @@
 
 class ServiceLevelAgreement(Document):
 	def validate(self):
+		self.validate_selected_doctype()
 		self.validate_doc()
 		self.validate_status_field()
 		self.check_priorities()
@@ -106,6 +107,23 @@
 			frappe.throw(_("Service Level Agreement for {0} {1} already exists.").format(
 				frappe.bold(self.entity_type), frappe.bold(self.entity)))
 
+	def validate_selected_doctype(self):
+		invalid_doctypes = list(frappe.model.core_doctypes_list)
+		invalid_doctypes.extend(['Cost Center', 'Company'])
+		valid_document_types = frappe.get_all('DocType', {
+			'issingle': 0,
+			'istable': 0,
+			'is_submittable': 0,
+			'name': ['not in', invalid_doctypes],
+			'module': ['not in', ["Email", "Core", "Custom", "Event Streaming", "Social", "Data Migration", "Geo", "Desk"]]
+		}, pluck="name")
+
+		if self.document_type not in valid_document_types:
+			frappe.throw(
+				msg=_("Please select valid document type."),
+				title=_("Invalid Document Type")
+			)
+
 	def validate_status_field(self):
 		meta = frappe.get_meta(self.document_type)
 		if not meta.get_field("status"):
@@ -247,9 +265,15 @@
 		]
 
 	customer = doc.get('customer')
-	or_filters.append(
-		["Service Level Agreement", "entity", "in", [customer] + get_customer_group(customer) + get_customer_territory(customer)]
-	)
+	if customer:
+		or_filters.extend([
+			["Service Level Agreement", "entity", "in", [customer] + get_customer_group(customer) + get_customer_territory(customer)],
+			["Service Level Agreement", "entity_type", "is", "not set"]
+		])
+	else:
+		or_filters.append(
+			["Service Level Agreement", "entity_type", "is", "not set"]
+		)
 
 	default_sla_filter = filters + [["Service Level Agreement", "default_service_level_agreement", "=", 1]]
 	default_sla = frappe.get_all("Service Level Agreement", filters=default_sla_filter,
@@ -361,11 +385,18 @@
 	sla = get_active_service_level_agreement_for(doc)
 
 	if not sla:
+		remove_sla_if_applied(doc)
 		return
 
 	process_sla(doc, sla)
 
 
+def remove_sla_if_applied(doc):
+	doc.service_level_agreement = None
+	doc.response_by = None
+	doc.resolution_by = None
+
+
 def process_sla(doc, sla):
 
 	if not doc.creation:
diff --git a/erpnext/support/doctype/service_level_agreement/service_level_agreement_dashboard.py b/erpnext/support/doctype/service_level_agreement/service_level_agreement_dashboard.py
deleted file mode 100644
index 22e2c37..0000000
--- a/erpnext/support/doctype/service_level_agreement/service_level_agreement_dashboard.py
+++ /dev/null
@@ -1,13 +0,0 @@
-from frappe import _
-
-
-def get_data():
-	return {
-		'fieldname': 'service_level_agreement',
-		'transactions': [
-			{
-				'label': _('Issue'),
-				'items': ['Issue']
-			}
-		]
-	}
diff --git a/erpnext/support/doctype/service_level_agreement/test_service_level_agreement.py b/erpnext/support/doctype/service_level_agreement/test_service_level_agreement.py
index b07c862..a34124f 100644
--- a/erpnext/support/doctype/service_level_agreement/test_service_level_agreement.py
+++ b/erpnext/support/doctype/service_level_agreement/test_service_level_agreement.py
@@ -244,6 +244,13 @@
 		applied_sla = frappe.db.get_value('Lead', lead.name, 'service_level_agreement')
 		self.assertEqual(applied_sla, lead_sla.name)
 
+		# check if SLA is removed if condition fails
+		lead.reload()
+		lead.source = None
+		lead.save()
+		applied_sla = frappe.db.get_value('Lead', lead.name, 'service_level_agreement')
+		self.assertFalse(applied_sla)
+
 	def tearDown(self):
 		for d in frappe.get_all("Service Level Agreement"):
 			frappe.delete_doc("Service Level Agreement", d.name, force=1)