I am running Wordpress 4.6.1 with Atahualpa 3.7.24 and have encountered a baffling problem. The site seems to work fine and displays properly when I call it up in my browser. But Google returns a 500 server error when I test the site with Google Fetch. I get the same error when I test it with web-sniffer.net.

After much searching, I changed to the default Twenty-Fifteen theme and the problem went away, which suggests the problem is being caused by the Atahualpa theme.

I switched to Atahualpa 3.7.22 and encountered the same problem. There must be a conflict somewhere, but where?

I tried deactivating all my plugins, but still got the same result.

Oddly, I have Wordpress builds in subdirectories running Atahualpa and have no problem getting the correct header responses from them.

I should point out that the home wordpress build is in the root directory.

The site is www.theimproper.com

Any suggestions will be greatly appreciated.

Have you looked at your servers error.log and/or talked to your host's support.

More than likely it is a problem with a plugin. While viewing the site in Safari and looking at the source, I do see an exception being caught....

Ok... think you are right. Appears to have had a plugin conflict with caching. I'll have to see how it goes, but all good with the theme.