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Oracle Error


Just loaded this application, and i’m getting the following error trying to connect:

ORA-12528-TNS:listener: all appropriate instances are blocking new connections.

I’m trying to connect to oracle XE for the first time but can’t seem to do it.

Any help would be appreciated.


ORA-12528: TNS:listener: all appropriate instances are blocking new connections

Cause: All instances supporting the service requested by the client reported that they were blocking the new connections. This condition may be temporary, such as at instance startup.

Action: Attempt the connection again. If error persists, then contact the administrator to check the status of the instances.

Check instance status with sql:

select instance_name, HOST_NAME, status, to_char(STARTUP_TIME,‘ hh24:mi:ss’) started from v$instance;
select name,open_mode,database_role from v$database;

where status column should be open (not started or mounted). and second query should confirm that (in a case of RAC instances).

if status is “open” then try next sql:

sqlplus "/as sysdba"
alter system disable restricted session;

which will terminate special kind of session restriction for privileged users.

Alse check listener staus with:

lsnrctl status

if you still get error, please give us output of next commands (full!):

sqlplus "/as sysdba"
shutdown immediate;
startup force;


Thanks, but I have no idea what you’re asking me to do. SQL? Where am I supposed to do that? The query window has all my buttons greyed out. I can’t run anything. Could I have specific directions, please.

Also, I re-installed XE 11g. I’m getting the following error:

ORA-12545: Connect failed because target host or object does not exist

I’m not sure what’s going on. I entered my SYSTEM and my password correctly. Apologies for my frustration, but I’ve been trying to create a simple database and this taken 2 whole days of my time.


try all commands from command prompt.

You invoke command prompt by Start|Run|cmd

then try all mine commands and output you get.