I've seen this when...
- When connecting to an Oracle 11.2 or older database from ORDS 17.4 or
ORDS 18.x.
I still have some 11.2 databases and I can't use anything above ORDS 3.0.12
for them. From ORDS 17.4 onward they changed the Oracle client version used
in ORDS and it doesn't appear to be backwards compatible. I was having
loads of trouble with ORDS 18.x and eventually Colm Divily suggested I
switch back and it's fine now. I now have:
DB 11.2 : ORDS 3.0.12
DB 12.1 + : ORDS 18.2
Those are fine for me.
2) If you have done an APEX upgrade since the ORDS install you will either
have to do an ORDS validate, or reinstall ORDS to fix some permissions. The
APEX upgrade trashes some permissions ORDS needs, and 3 views won't compile.
https://oracle-base.com/articles/misc/oracle-rest-data-services-ords-installation-on-tomcat#ords-validate
3) I think it's happened when I've forgotten to run the EPG config during
the APEX installation.
https://oracle-base.com/articles/misc/oracle-application-express-apex-5-0-installation#epg-configuration
4) I guess the most obvious, it's happened when I've used the wrong
passwords or had locked DB users. :)
Cheers
Tim...
Cheers
