KB40604: What does the error message "User session is invalid when trying to add new commands in" in the MicroStrategy Web 9.x logs mean?

SYMPTOM
When an user tries to access Strategy Web 9.x the following error message is shown on the screen.
Sample Code/Error

MsiSessionManager::IsUserLoggedIn(): user session is invalid when trying to add new commands in. (com.Strategy.webapi.MSTRWebAPIException)

 
CAUSE:
The error message can appear for the following two cases:

• When the user’s session cannot be found in the Intelligence Server’s session table. Look for the following entry in the user trace:
   
  
  Sample Code/Error
  
  

  
  MsiSessionManager::GetUserSession(): session %1 is not found in session table.

  
  
  
  
• When the user’s session is in the Server’s session table but this session is marked as logged out. Look for the following entry in user trace:
   
  
  Sample Code/Error
  
  

  
  MsiSessionManager::GetUserSession(): User %1`s session %2 has been closed.

  
  
  
  

In order to reach one of the above states, the user must have had two web browser windows opened with the same session. When the user logs out of one of the browsers, they will see the error in the other browser window.
 
ACTION
The issue can usually be resolved by one of the following actions:

1. Purge the Web caches following KB42534 - How to Purge Web Caches in Strategy Web and Web Universal, followed by clearing the web browser caches.
   
2. Use Internet Explorer in InPrivate browsing. This means that the browser will not try to reuse any cached content.
   

To prevent this from happening, make sure users log out or do not open multiple browsers at the same time, causing the session to be cached and reused even though it may have already expired.