KB212476: "Error: SQLEngine got an Exception from DFC: [DFCENGINE] Engine Logic: Unexpected error in joining a group of attributes" is received when running a report containing two related attributes in MicroStrategy

SUMMARY
This document outlines a SQL engine error encountered in Strategy when running a report that contains two indirectly attributes (specific conditions need to be met). This issue has been classified as a defect and is not scoped to be fixed in any upcoming release. 
SYMPTOM
In Strategy, the following error message is received when running a report that contains two related attributes: 
 

Status: Initialization Failed
Error: SQLEngine got an Exception from DFC: [DFCENGINE] Engine Logic: Unexpected error in joining a group of attributes.

1. These two attributes don’t have a direct Parent-Child relationship.
2. These two attributes have a common grandchild attribute.
3. One or neither of the attribute is the key of their respective lookup table. eg., attribute 1 is not the key for its lookup table - LU1; attribute 2 is not the key for its lookup table - LU2.

 
STEPS TO REPRODUCE 
The following steps are based on the Strategy Tutorial project. 
 

1. Edit attribute "Strategy User" in the Geography hierarchy to make it a child of the attribute “Manager” with one-to-one relationship. (Relationship does not matter).
2. Create a new attribute "Region Name" as a one-to-one child of Region. ID form must be column REGION_NAME from LU_REGION Table.
3. Update the Schema.
4. Create a new report with attribute 'Manager' on the report template.
5. Create a custom report filter as "Manager@ID exactly Region@ID"
6. Execute the report to see the error message.  

CAUSE
This is a known issue with Strategy Engine.
 
ACTION
This issue is currently not scoped to be fixed in any upcoming Strategy release.  
The Strategy Internal Reference Number for the issue discussed in this technical note is 352688.