KB442586: “java.lang.NullPointerException” error occurs when logging MicroStrategy web 10.x and above

SYMPTOM:
 
Strategy web 10.x and above, “java.lang.NullPointerException” error occurs when logging web after configure “Restrict each Database Connection to one warehouse query at a time” in Developer.
 

 
 
Below entries are logged in DSSErrors.log:
"Cannot perform catalog operation because no Database Connection is associated with the provided Database Instance." 
 
 
REPRODUCING STEPS IN TUTORIAL:
 

1. In Strategy 10.x and above, create a new Database instance in Developer. Check "Restrict each Database Connection to one warehouse query at a time" and select the "Database connection", then save the DB instance as shown below:

1. Login Strategy Web and click the DB role for connection, java.lang.NullPointerException error pops out.

   
Background why Restrict DB was introduced:
 
For DB2 MVS database, it has a problem when creating or deleting tables concurrently. When trying to do so, it deadlocks. A solution for this is to create a couple of databases where the temp tables will be created and destroyed. Each database may not be used by more than one concurrent connection. Therefore, Restrict DB was introduced. It takes a collection of connection definitions and will decide which one to use.
   
 
CAUSE:
 
When creating a new Database instance in Developer, check "Restrict DB" and select multiple DB connections, there's no default setting for DB connection, therefore the system doesn’t know which DB connection to choose and the error pops.
  
 
WORKAROUND:
 
Save the DB instance as a common one first and then edit it and check on the option "Restrict each Database Connection to one warehouse query at a time", as well as selecting DB connections.
 
In this way, there will be a default DB connection and it'll work on the Web client.
 
  
Article Reference Number: KB442586