KB46023: Multiple caches for reports located in the same folder are getting deleted after applying an ACL to the folder in MicroStrategy 9.x

SYMPTOM:
 
After applying a folder level ACL, all existing caches for reports and documents located in that folder are deleted. Cache Trace shows the following entry for the reports with removed caches.
 
Sample Code/Error
 Cache with ID XXXXXXXXXXXXXXXXXXXXXXXXXX is removed by hCleanUpCache 1151
 
STEPS TO REPRODUCE:

• Run a report in Strategy Desktop and check the cache monitor to make sure a cache was created with status R, L, U, F as shown below.
   
  

• Check the version ID of the report.
   
  

• Right-click on the folder in which the report is located and select properties.
• In the properties window, select the "Security" option. Make any desired changes to permissions and select all check boxes corresponding to "Apply Changes in permissions to all children objects"
   
  

• Check the version ID of the report again and notice that it has changed.
   
  

• Upon checking the cache monitor, the user will notice that the cache has been deleted from the project.

CAUSE:
 
The behavior observed above is expected because when permissions are changed at the folder level and the "Apply Changes in permissions to all children objects" option is selected, the changes will propagate to all objects located within that folder which will automatically change the version IDs of all the objects in that folder. Once the version ID of an object (e.g., report) changes, all associated caches for that object are automatically invalidated.