OK maybe it’s an Instagram API change:
“Due to recent changes in the Instagram API it is no longer possible to display photos from other Instagram accounts which you do not have access to.” (from the Smash Balloon plugin)
I have it working in 4.1.1 as advertised. It looks like it’s just a simple plugin that adds a line of code to .htaccess. Are you sure your site is using an .htaccess file?
Hi Sam,
I too saw the “Warning” error with 0.9.9.6, but once I requested and installed the API key the warning went away.
I hope this helps. Amazing plugin. Keep up the great work!