KB324047: “Inbox message result is not ready.” error occurs when executing a document in MicroStrategy Web 10.x

SUMMARY
This document describes a known issue in Strategy Analytics Enterprise 10.x that may occur when executing a report service document from Strategy Web.
 
SYMPTOM
In Strategy Analytics Enterprise 10.x users may notice the following error message when executing documents from Strategy Web:
 

(Inbox message result is not ready.)

 
STEPS TO REPRODUCE
The error will occur when the following conditions are met:

1. The “Background Execution” option is enabled under the Strategy Intelligence Server configuration
2. Statistics logging is enabled for the project
3. The document was created with a prompt, and when saving the document the option "Do not display prompt and use the current answers as the default answers" was selected.
4. The document hits an XML cache during execution

Note:
The error will only occur when all of the above conditions are met. If 3 or fewer of the above conditions are true the error will not occur.
 
CAUSE
This is a known issue in Strategy Secure Enterprise 10.x.
 
ACTION
The issue has been fixed in Strategy Secure Enterprise 10.4.3 and  Strategy Secure Enterprise 10.7. 
WORKAROUND
One of the following workarounds can be used to avoid this issue: 
 
1. On Strategy Web 10.x project preferences, disable the option to automatically add reports and documents to History List (OR)
2. Disable document caching (OR)
3. Disable Statistics collection on the project.