Ora-12850: could not allocate slaves on all specified instances

Toad for Oracle & DevOps Toolkit
1

I'm getting this error on TOAD on a 4-Node RAC, when ever using session browser with 'user rac views" checked.
ORA-12850: COULD NOT ALLOCATE SLAVES ON ALL SPECIFIED INSTANCES: 4 NEEDED, 3 ALLOCATED

2

This is not a Toad bug. There is probably some issue with your database.

You can turn on Spool SQL (Main menu -> Database -> Spool SQL -> Spool to Screen) to see the SQL that Toad is running which causes the error.

You will likely get the same error if you run that SQL from SQL*Plus. If you aren't sure how to solve it, please talk to your DBA or Oracle support.

-John