ORA-28759: failure to open file

If any program or query is failed with error ORA-28759, its should be access/permission issue to the wallets location in database server.

Ex:  In my database there is DB link which link to other schema, if i check the db link test i got the below error.

SQL> select count(*) from tab@TEST_DBL;

select count(*) from tab@TEST_DBL

                         *

ERROR at line 1:

ORA-28759: failure to open file

I find the tnsping is not working and got below error.

TNS-12560: TNS:protocol adapter error

i find there is permission issue to wallet location even directory owner is oracle

oracle@labserver:[DB->TEST]$cd /home/oracle/wallet

-bash: cd: /home/oracle/wallet: Permission denied

i check the permission is not sufficient.

drw-r----- 2 oracle oinstall  113 Nov  5 02:00 wallet

Changed to 755 to oracle and got access to directory and issue resolved. 

Like this for any reason if wallet is configured in listener/sqlnet.ora and does not have access wallet directory for oracle user then this issue arise.

Fix by fixing access issue to wallet location.