First check table space quota for all user or for specific user using sql query.

DBA_TS_QUOTAS describes tablespace quotas for all users.
USER_TS_QUOTAS describes tablespace quotas for the current user.

select * from user_ts_quotas;
OR
select * from dba_ts_quotas;

In result you can check MAX_BYTES – User’s quota in bytes, or -1 if no limit. If you want your user have no restrictions on the amount of data it puts in USERS, run:

ALTER USER <your user> quota unlimited on USERS;

or if you want to limit the quota to, say, 10 MB:

ALTER USER <your user> quota 10M on USERS;