Hi Manju 

Thanks for posting in the community - sorry for the trouble you're experiencing! Would you mind accessing your account and attempting to restore your document using a Chrome incognito window? This will start a new cookie session and disable any extensions which may be causing this issue. Additionally performance-related issues are often related to the internet connection. Can you please try to restore your document while using a different internet connection? A mobile hotspot may be useful for this. 

If those tips don't resolve the issue please submit a ticket here so our team can take a closer look. Thanks!