Improve error message when cached Manifest is out of date
Improve error message when cached Manifest is out of date

xiao-chen/dist_test,umbrant/dist_test,umbrant/dist_test,cloudera/dist_test,xiao-chen/dist_test,xiao-chen/dist_test,cloudera/dist_test,cloudera/dist_test,umbrant/dist_test,umbrant/dist_test,xiao-chen/dist_test,cloudera/dist_test