Search notes:

ORA-01950: no privileges on tablespace '…'

Most likely, the user has no quota granted on the tablespace in which he wants to create a table or index.

select 
   bytes,
   max_bytes,
   dropped
from
   dba_ts_quotas
where
   tablespace_name = '…' and
   username        = '…'
;

A quota can be assigned to the user with

alter  user USER_ABC quota 500 GB    on TABLESPACE_XYZ;
alter  user USER_ABC quota unlimited on TABLESPACE_XYZ;

Alternatively, the UNLIMITED TABLESPACE system privilege can be given to the user.

Misc

As part of Oracle's program to improve error messages, the text has changed to ORA-01950: The user … has insufficient quota on tablespace … .