Stalin had detailed intelligence about the German invasion in 1941, Roosevelt had detailed intelligence about Pearl Harbor and Hitler was in possession of the plans for the Normandy Invasion. Yet all of them failed to act.
Hindsight is always 20/20.
With respect to Stalin's failure, I am just about finished reading
Grand Delusion: Stalin and the German Invasion of Russia, by Gabriel Gorodetsky, based on newly released archival material, especially in Russia. Turns out most of the intel Stalin got was sanitized to tell him what his underlings knew he wanted to hear. The few times people were brave enough to tell him otherwise, he blew his stack. I imagine it was the same with Hitler and Normandy.
As for FDR and Pearl Harbor, I think the latest info confirms the conspiracy theories, so that that was not really an intelligence failure.