diff --git a/ucc-umc-setup/umc/python/uccsetup/__init__.py b/ucc-umc-setup/umc/python/uccsetup/__init__.py
index 30ef079..4be85ad 100644
--- a/ucc-umc-setup/umc/python/uccsetup/__init__.py
+++ b/ucc-umc-setup/umc/python/uccsetup/__init__.py
@@ -99,8 +99,8 @@ class Instance(Base, ProgressMixin):
 			'citrix_url': ucr_policy.get('citrix/webinterface', ''),
 			'citrix_autologin': ucr_policy.get('lightdm/autologin/session') == 'XenApp' and ucr_policy.is_true('lightdm/autologin'),
 			'browser_url': ucr_policy.get('firefox/startsite', ''),
-			'download_size_thinclient': thinclient_image.total_download_size,
-			'download_size_desktop': desktop_image.total_download_size,
+			'download_size_thinclient': thinclient_image.total_download_size if thinclient_image else 0,
+			'download_size_desktop': desktop_image.total_download_size if desktop_image else 0,
 		}
 
 	@file_upload