No privileges on tablespace 'USERS'
The cause of the error is SEGMENT CREATION DEFERRED.

This feature of Oracle was introduced ~11gR2.  It allows large applications to CREATE TABLE for everything in the application without using disk space.  The application will use 0 bytes for the tables that the customer won't use. (eg they aren't licensed for the feature(s) that uses those tables)

This feature has the side-effect of allowing you to CREATE TABLE on a tablespace which you don't have a quota.

to fix

Your CREATE USER needs to include a QUOTA clause in order to add data to that tablespace.  You could easily ALTER USER to add a quota.

There is also the over powering UNLIMITED TABLESPACE system privilege.  It grants the user QUOTA UNLIMITED on all tablespaces (including SYSTEM and SYSAUX -- which you shouldn't use).  This privilege seems to go against the security concept of "least privileges".  Use it sparingly.