Many iPhone users after upgrading to iOS 11/11.3 are facing issue that after the upgrade #images, gifs and images are no longer showing in iMessage. The issue is happening across all type of iPhones 6/7 and even with latest iPhone X/8. For some iPhone users the #images only work with WIFI. As you must be aware that iMessage are enabled for certain countries but the issue is still reported from those one.
The #images not working in iphone is reported to happen after the user upgrade to iOS 11, and was working fine with iOS10. This very annoying for many users as any search for #images or GIFs to add to iMessage is saying "no images found" even with a simple search such as good night. Hard Reset or even a factory reset to iPhone does not seems to fix the issue. And this is quite sure that some changes in iOS 11 have made #images to work in iMessages.
How to fix #images not working in iPhone:
Fix 1: Enable mobile data for #hastag images
Go to Settings-> cellular data and find #hashtagimages and make sure to turn it on, the settting is off for many users facing issues with imessages #images. (Settings -> Cellular -> HashtagImages -> “ON”) If you still don’t see it try changing the region to the UK and then back to the US and restart the phone and put the iPhone language to English(UK).
Fix 2: Use 3rd party App Giphy
Giphy app is basically the same thing. It's free in the app store, and you just add it to iMessage as you would add Images.