I’ve run into this exact confusion with LUIS prebuilt domains before, so let’s walk through the most likely reasons you’re seeing this discrepancy:

• The domain was retired but docs haven’t caught up
  Microsoft occasionally phases out older prebuilt domains from the live luis.ai interface to prioritize newer tools or consolidate overlapping functionality. It’s common for documentation to lag behind these changes, so even though the page lists "Utilities", it might no longer be available in the actual UI.

• You’re searching in the wrong section
  Wait a second—you mentioned using the "Add prebuilt domain entities" button. But full prebuilt domains are added through a separate "Add prebuilt domains" option, not the entities section. If you’re only looking for entities, you won’t find the complete "Utilities" domain there. Double-check your navigation to make sure you’re in the right place.

• Regional or tier limitations
  Some prebuilt domains aren’t available across all Azure regions or LUIS service tiers. Verify that your LUIS resource is hosted in a region that supports the domain (if it still exists) and that you’re on a tier that grants access to all prebuilt offerings.

• Functionality was merged into another domain
  Microsoft sometimes rolls features from deprecated domains into broader ones. The "Utilities" domain’s intents (like help, cancel, or confirmation) are often covered by the "General" prebuilt domain now. It’s worth checking there to see if it has what you need.

If you specifically need the exact structure from the old "Utilities" domain, you can manually recreate its intents and entities using the details from the documentation as a guide.

内容的提问来源于stack exchange，提问作者Kevin D.