Certain third-party Mac NTFS software and/or connected partitions with versions of Microsoft Windows that contain the NTFS filesystem may cause this issue. Follow these steps:
- From the Apple menu, choose System Preferences.
- From the View menu, choose Spotlight.
- Click the Privacy tab and then the "+" sign to add your NTFS filesystems, partitions or connected drives.
If you're using Boot Camp, select your BOOTCAMP drive or partition from the sidebar on the left side of the folder selection sheet, then click Choose, to prevent this issue from occurring.
Some third-party NTFS utilities have their own System preferences that will also allow you to perform the same function as using the Privacy tab of the Spotlight preferences, or will allow you to temporarily disable them.
Once the connected NTFS resource is excluded in the Spotlight preferences, the Mac App Store should remain responsive when you click the Updates icon.