diff --git a/frappe/core/doctype/doctype/doctype.py b/frappe/core/doctype/doctype/doctype.py
index d2d8d8a621..ac40bce2f3 100644
--- a/frappe/core/doctype/doctype/doctype.py
+++ b/frappe/core/doctype/doctype/doctype.py
@@ -15,7 +15,7 @@ from frappe.model.document import Document
 from frappe.custom.doctype.property_setter.property_setter import make_property_setter
 from frappe.desk.notifications import delete_notification_count_for
 from frappe.modules import make_boilerplate
-from frappe.model.db_schema import validate_column_name, validate_column_length
+from frappe.model.db_schema import validate_column_name, validate_column_length, type_map
 import frappe.website.render
 
 # imports - third-party imports
@@ -205,6 +205,8 @@ class DocType(Document):
 	def on_update(self):
 		"""Update database schema, make controller templates if `custom` is not set and clear cache."""
 		from frappe.model.db_schema import updatedb
+		self.rename_custom_fields()
+
 		updatedb(self.name, self)
 
 		self.change_modified_of_parent()
@@ -236,6 +238,28 @@ class DocType(Document):
 		if self.name in frappe.local.meta_cache:
 			del frappe.local.meta_cache[self.name]
 
+	def rename_custom_fields(self):
+		if not (frappe.db.table_exists(self.name) and frappe.db.table_exists("Custom Field")):
+			return
+		fields = [d.fieldname for d in self.fields if d.fieldtype in type_map]
+		custom_field_conflict = frappe.db.sql('''select name, fieldname from
+				`tabCustom Field`
+			where
+				fieldname in ({0})'''.format(', '.join(['%s'] * len(fields))), fields, as_dict=True)
+
+		for custom_field in custom_field_conflict:
+			if frappe.db.has_column(self.name, custom_field.fieldname):
+				frappe.db.commit()
+				column_type = frappe.db.get_column_type(self.name, custom_field.fieldname)
+
+				if not frappe.db.has_column(self.name, custom_field.fieldname + '_custom'):
+					frappe.db.sql('alter table `tab{0}` change `{1}` `{1}_custom` {2}'.format(self.name,
+						custom_field.fieldname, column_type))
+
+				# rename in custom field
+				frappe.db.set_value('Custom Field', custom_field.name, 'fieldname', custom_field.fieldname + '_custom')
+
+
 	def sync_global_search(self):
 		'''If global search settings are changed, rebuild search properties for this table'''
 		global_search_fields_before_update = [d.fieldname for d in
diff --git a/frappe/database.py b/frappe/database.py
index 990ddf37be..bc0697ab9e 100644
--- a/frappe/database.py
+++ b/frappe/database.py
@@ -776,9 +776,9 @@ class Database:
 		"""Return true of field exists."""
 		return self.sql("select name from tabDocField where fieldname=%s and parent=%s", (dt, fn))
 
-	def table_exists(self, tablename):
-		"""Returns True if table exists."""
-		return ("tab" + tablename) in self.get_tables()
+	def table_exists(self, doctype):
+		"""Returns True if table for given doctype exists."""
+		return ("tab" + doctype) in self.get_tables()
 
 	def get_tables(self):
 		return [d[0] for d in self.sql("show tables")]
@@ -842,6 +842,10 @@ class Database:
 		"""Returns True if column exists in database."""
 		return column in self.get_table_columns(doctype)
 
+	def get_column_type(self, doctype, column):
+		return frappe.db.sql('''SELECT column_type FROM INFORMATION_SCHEMA.COLUMNS
+			WHERE table_name = 'tab{0}' AND COLUMN_NAME = "{1}"'''.format(doctype, column))[0][0]
+
 	def add_index(self, doctype, fields, index_name=None):
 		"""Creates an index with given fields if not already created.
 		Index name will be `fieldname1_fieldname2_index`"""
diff --git a/frappe/desk/doctype/desktop_icon/desktop_icon.py b/frappe/desk/doctype/desktop_icon/desktop_icon.py
index 6d5e2d6ab5..1874e0725c 100644
--- a/frappe/desk/doctype/desktop_icon/desktop_icon.py
+++ b/frappe/desk/doctype/desktop_icon/desktop_icon.py
@@ -352,7 +352,10 @@ def sync_from_app(app):
 			m['_doctype'] = m.pop('doctype')
 
 		desktop_icon.update(m)
-		desktop_icon.save()
+		try:
+			desktop_icon.save()
+		except frappe.exceptions.UniqueValidationError:
+			pass
 
 	return modules_list
 
diff --git a/frappe/utils/help.py b/frappe/utils/help.py
index 45971820c0..c76e977dd8 100644
--- a/frappe/utils/help.py
+++ b/frappe/utils/help.py
@@ -15,6 +15,8 @@ from bs4 import BeautifulSoup
 import jinja2.exceptions
 from six import text_type
 
+import io
+
 def sync():
 	# make table
 	print('Syncing help database...')
@@ -55,7 +57,7 @@ class HelpDatabase(object):
 		self.global_help_setup = frappe.conf.get('global_help_setup')
 		if self.global_help_setup:
 			bench_name = os.path.basename(os.path.abspath(frappe.get_app_path('frappe')).split('/apps/')[0])
-			self.help_db_name = hashlib.sha224(bench_name).hexdigest()[:15]
+			self.help_db_name = hashlib.sha224(bench_name.encode('utf-8')).hexdigest()[:15]
 
 	def make_database(self):
 		'''make database for global help setup'''
@@ -135,9 +137,9 @@ class HelpDatabase(object):
 					for fname in files:
 						if fname.rsplit('.', 1)[-1] in ('md', 'html'):
 							fpath = os.path.join(basepath, fname)
-							with open(fpath, 'r') as f:
+							with io.open(fpath, 'r', encoding = 'utf-8') as f:
 								try:
-									content = frappe.render_template(text_type(f.read(), 'utf-8'),
+									content = frappe.render_template(f.read(),
 										{'docs_base_url': '/assets/{app}_docs'.format(app=app)})
 
 									relpath = self.get_out_path(fpath)
@@ -235,7 +237,7 @@ class HelpDatabase(object):
 
 			# files not in index.txt
 			for f in os.listdir(path):
-				if not os.path.isdir(os.path.join(path, f)):
+				if not os.path.isdir(os.path.join(path, f)) and len(f.rsplit('.', 1)) == 2:
 					name, extn = f.rsplit('.', 1)
 					if name not in files \
 						and name != 'index' and extn in ('md', 'html'):