If Ads are being displayed in You tube and in Blogs there is only Blank space, only the concerned authorities can clarify. But wait for some time before you contact Google.

Ok, but initially ads were being displayed both on youtube and blogs, and my adsense account was approved before 3 months. I have asked the same question on other community site and they said that ads are not being displayed on the same IP address or may be your area being not targeted by advertisers to display ads. But if this was the reason, then ads will not be displayed on youtube also.

Add normally cone on depending on your content,atleast that's how it is on my blog..

Manoj Kumar Lamba wrote:

Ok, but initially ads were being displayed both on youtube and blogs, and my adsense account was approved before 3 months. I have asked the same question on other community site and they said that ads are not being displayed on the same IP address or may be your area being not targeted by advertisers to display ads. But if this was the reason, then ads will not be displayed on youtube also.

 Because  the Ads are stopped only in your Blog, you have to watch for some time, if the error gets adjusted after some time, its OK. That's why you have to watch for some time.

There is no concept like error when it comes to placement of ads since everything is automated ... Either they have not been placed properly by the member which means you have to change the settings and also add some new content to your blog..