Standalone ArcGIS Server can no longer print its own web services. The web services are unsecure and are externally accessible. The print service returns the following error "Error executing tool. Export Web Map Task : Failed to create layer from service at ..." Seems to happen with all services hosted on the site. I have taken a look at the JSON for the request and it looks good. Our other standalone ArcGIS Server has no issue printing when using the same parameters and web services. In addition, the print service in question is able to print web services coming from other sites. So it only seems to be an issue with printing web services hosted on the same site.
At first I thought it could be a certificate issue, but the CA signed certificate and its intermediates have all been imported into the ArcGIS Server certificate store. And the web server certificate has been set.
I have also tried restarting the print service, but no luck.
