In Toad 11.6, get Ora-01031 error trying to connect to 12c database
When connecting to an Oracle 126.96.36.199 database, using Toad 188.8.131.52, with a regular user, the following error message is received.
"Ora-01031 Insuficient priviliges"
After this The connection works ok.
When connecting to Oracle 10.2.0.4 database, with the same regular user, there is no error.
Both have all privileges to connect and resource.
Oracle 184.108.40.206 changed some things in the data dictionary that are causing this. Specifically, the table SYS.USER$ is no longer included in the SELECT ANY DICTIONARY system privilege. So what's happening is that Toad is detecting that the user has SELECT ANY DICTIONARY, and assuming because of that, the user can select from the SYS.USER$ table.
RESOLUTION #1: Grant SYS.USER$ to the user.
RESOLUTION #2: Upgrade to the current version of Toad, which you can download here.