Third party hosted website images not displayed on IE11 and the behaviour is random

Question

Hi All we are trying to access a vendor hosted site from a large organisation ( with lot of IE settings locked). The website some times doesn't display most of the images for few users, and the issue occurs randomly (persistent for few days) and mostly happens on IE web browser where as it works fine on Chrome on the same machine. All the domains requested by the vendor has been whitelisted. In IE developer tools : - Most of the images status code is 307. -The content type for non displayed images is text/html and for the ones displayed its png. -Other observation is the non displayed images in response header have a url related to https://gateway.zscloud.net:443/aud?orgurl==https .............................

Answer 1

Vendor was hosting images on different domains, these domains were not whitelisted in Zscaler. The redirection request for images was blocked by zscaler if it was not cached.

IE was the default browser in the organisation and the user base using IE was larger. Chrome user was very low. Both browser caching also works differently. Hence the issue was more predominant on IE.

Resolution: Identified all the domains that were not whitelisted ( from Developer tools) and got it validated from vendor. After whitelisting the issue is no more encountered. Vendor have also updated their documents for future reference.