ADOP Fails With Error Unable to Find Appltop_id R12.2

When running ADOP with phase=fs_clone, it fails with following error:
[STATEMENT] Admin node : "appltestappltest"
[PROCEDURE] [END   2014/06/30 18:10:02] Determining admin node
[STATEMENT] Value of nodes : "appltest,dbtest"
[UNEXPECTED]Unable to find appltop_id for the host appltestappltest from database
Cause
 The SQL statement ADOP uses to get the admin node name is:
   select node_name from FND_OAM_CONTEXT_FILES
   where NAME not in ('TEMPLATE','METADATA','config.txt') and
   CTX_TYPE='A' and (status is null or upper(status) in ('S','F'))
   and EXTRACTVALUE(XMLType(TEXT),'//file_edition_type') = 'run'
   and EXTRACTVALUE(XMLType(TEXT),'//oa_service_group_status[@oa_var=''s_web_admin_status'']')='enabled'
   and EXTRACTVALUE(XMLType(TEXT),'//oa_service_list/oa_service[@type=''admin_server'']/oa_service_status')='enabled';
Execute above SQL statement manually, it returns:
node_name
appltest
appltest

The problem is due to the table FND_OAM_CONTEXT_FILES has duplicate entries.
Solution:
1. Back up the table FND_OAM_CONTEXT_FILES table.
2. Delete the duplicate record in table FND_OAM_CONTEXT_FILES reflected in the following select:
select node_name from FND_OAM_CONTEXT_FILES
   where NAME not in ('TEMPLATE','METADATA','config.txt') and
   CTX_TYPE='A' and (status is null or upper(status) in ('S','F'))
   and EXTRACTVALUE(XMLType(TEXT),'//file_edition_type') = 'run'
   and EXTRACTVALUE(XMLType(TEXT),'//oa_service_group_status[@oa_var=''s_web_admin_status'']')='enabled'
   and EXTRACTVALUE(XMLType(TEXT),'//oa_service_list/oa_service[@type=''admin_server'']/oa_service_status')='enabled';
Please check the column "NAME" and "PATH" to identify the duplicate records.
The duplicate record may come from the source environment.
Then use statement "delete from FND_OAM_CONTEXT_FILES where <duplicate record conditions>" to delete the record and commit.
Please note, the standard process to populate the table FND_OAM_CONTEXT_FILES  is to run autoconfig.
Since in this case ADOP cycle is running, above action plan is a workaround. Please perform above action under Oracle support's instruction.
3. Re-run the select above to ensure it returns the correct value.
4. Retest the issue.