Tested the issue in Android and could reproduce the issue. Observed the above mentioned error message

Steps Followed:
1. Launched Chrome Browser.
2. Navigated to Google images
3. Clicked on image
4. Long tapped on image, tapped on Search Google for this image (Refer video)
5. Observed the above mentioned error message

Chrome versions tested:
63.0.3239.111, 65.0.3295.0

OS
Android 8.0.0, 7.0.0

Android Devices
8.0.0; Pixel XL Build/OPR1.170623.027, 7.0.0; SM-J710F Build/NRD90M

Below is the bisect info
=======================
Chrome Good Build -- 61.0.3163.0
Chrome Bad Build  -- 62.0.3164.0

Manual CL:
https://chromium.googlesource.com/chromium/src/+log/61.0.3163.0..62.0.3164.0?pretty=fuller&n=10000

Unable to provide the tool bisect info as couldn't get the context menu on clicking the image.

From the above revision range suspecting the following change have fixed the issue and assigning the issue to the owner concerned--
https://chromium.googlesource.com/chromium/src/+/9e24929e2983a0bd95da806f307cfdffc5367688

@ben -- Could you please look into the issue as the above mentioned CL looks relates Search in Clank and also help us in assigning the issue to appropriate owner if it's not related to your change

Please navigate to below link for log's and video--
go/chrome-androidlogs/795616

Thanks!!

I think Google images has changed something on its back end cause reverse search images is now working again.