Oracle Apex 5.1.4
ORDS 18
Tomcat 9.0
Apache 2.4
In attempting to add a table through the SQL Workshop - Object Browser; I get an ORA-01536 error:

I looked at the DB using this script and it looks like the tablespace has plenty of room.
SQL> select * From DBA_TABLESPACE_USAGE_METRICS;
TABLESPACE_NAME USED_SPACE TABLESPACE_SIZE USED_PERCENT
------------------------------ ---------- --------------- ------------
APEX 45840 131072 34.9731445
APEX51 43048 2523209 1.70608142
APEX_1680806080686133 1600 12808 12.4921924
APEX_5286416347703295 1248 12808 9.74391006
APEX_FILES 128 2472009 .005177975
SYSAUX 63096 2560329 2.46437079
SYSTEM 61440 76800 80
TEMP 0 2466274 0
UNDOTBS1 288 2488034 .011575405
USERS 328 1441792 .022749467
10 rows selected
I then looked and found that backups hadn't been running, leaving 100+ valid ARC (archivelog) files - So I ran two manual backups, which cleared out the old archive logs.
I then stopped and restarted the database. However, I'm still not able to create a new table??
What else can or should I be looking at in order to resolve this?
Thanks in advance...
Rich