GraphQL: How to resolve an HTTP Error 500

If you receive an HTTP Error 500 when accessing the http://[yoursite]/wfgen/graphql page, you can perform the following checks:

  • Verify that iisnode, URL Rewrite, and Node.js (with the correct version) are properly installed.

  • Verify that IIS Anonymous authentication mode is disabled in the graphql node.

  • Verify that the application pool identity has read/write access to the \graphql folder.

  • Verify that there are no duplicate entries in the web.config file (\wfgen\web.config and \wfgen\graphql\web.config). If so, remove the duplicates.

  • Verify the logs located in the \wfgen\graphql\iisnode folder on the IIS server.

To enable GraphQL logging, update the GraphQL web.config file (\wfgen\graphql\web.config) by changing the loggingEnabled property to true in the iisnode parameter:

<iisnode ....
loggingEnabled="true" 
logDirectory="iisnode" 
... />