Hello There,
The response is telling you that your purchase code is incorrect. I assume that you used the purchased code for X. Since the plugin is bundled in the theme, you do not have any purchase code for the plugin. This is only available and the support is only applicable if you have purchased a separate license for the plugin.
I have check the page and I could not replicate the issue. If you refresh the page in a very short interval of time, chances are, the error would appear in your end because the Instagram API returns a request timeout which usually happens if you send the same amount of request in a very short period of time. This is a way of the server rejecting your request for the moment to prevent the server from overloading.
I also noticed that you have updated Cornerstone to 3.1.2. Please make sure that your X theme is updated to. Right now it is still 6.0.4. I would recommend that you update X theme to 6.1.3 and Cornerstone 3.1.3 because we just release another update a few hours ago. Please do not forget to check the changelog (https://theme.co/changelog/) to know more what is included in the release.
Hope this helps.