Table comments corrupted (UTF8 issue?) when restoring database from Oracle 11 to Oracle 12

[kaiken]

We have restored our production database schemas (SysDB and UserDB) from an Oracle snapshot of HOPEX V1R3 / Oracle 11 to our test HOPEX V2 / Oracle 12 deployment.

The DBA has informed us that there is some data loss -- table column comments have become corrupted.  He sent a listing of to ~500 table column comments with the issue; most of them are the same issue: the accented "c" in Français has been replaced with a question mark.  The other few comments also seem to be accented characters or other special characters.

He has confirmed that both databases are using the same character set.

Has anyone experienced similar issues?  The DBA is looking for scripts to fix the data; Oracle will not provide at this point. 

Schema.Table_Name	Column Name	Comment
HOPEXENV01_DV01.Z1_P_C_0C750E4657322BA7	GBM_A_021D021F3D06003C	GenericLocalName (Fran?ais)
HOPEXENV01_DV01.Z1_P_C_0C750E4657322BA7	GBM_A_1E3125B43B600150	LanguageUpdateDate (Fran?ais)

[kaiken · Accepted solution]

Update -- our DBA re-attempted the export last night using the "traditional Oracle export method", and it was successful - no data corruption.

I gather we only need to use this method going from Oracle 11 to 12; we'll use snapshots for databases which are the same version.