Drawloop - Error: [CustomObjectName] does not exist

Issue

When creating a Visualforce page from a Custom Object, the following error occurs:
 

Resolution

Append "__c" to the end of the custom object.

Sample code: 

<apex:page standardController="Location__c"action="/apex/loop__looplus?sessionId={!$Api.Session_ID}&eid={!Location__c.Id}"></apex:page>

For more information, see Create a button to generate documents in Salesforce Lightning.