The only thing I found when looking at lab cases for "TNS:protocol adapter error" was that the oracle windows service is not started, probably on the destination host
I 'googled' the error, the first article seems to indicate that thsi is the problem
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::NO::P11_QUESTION_ID:431775600346873836
C:\Documents and Settings\tkyte>net stop oracleserviceora10gr1
The OracleServiceORA10GR1 service is stopping.........
The OracleServiceORA10GR1 service was stopped successfully
C:\Documents and Settings\tkyte>sqlplus scott/tiger
SQL*Plus: Release 10.1.0.4.0 - Production on Thu Sep 6 15:44:35 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-12560: TNS:protocol adapter error
Another possibility
https://community.oracle.com/thread/76240?tstart=0
When starting server manager the following error is generated:
ORA-12560: TNS:protocol adapter error occurred
Cause:
Oracle classify this as a 'generic protocol adapter error'. In my experience it indicates that Oracle client does not know what instance to connect to or what TNS alias to use.
Possible Remedies:
* If running on the server (or workstation) that is running the database (i.e. if the database is local to the machine) then try explicitly setting 'ORACLE_SID'. e.g.
set ORACLE_SID=<sid>
and then try again. If this works then consider whether to make the change permanent by specifying it as a system variable.
But, bottom line, this appears to be more of an Oracle issue, and not Data Protector