When running a query on a table containing some encrypted unicode data, through Toad for Oracle, and other columns containing English text or encrypted data stored in a VARCHAR2 column, Toad for Oracle throws error "ORA-29275: partial multibyte character".

It is found that the SQL*Plus 11g displays the query without getting ora-29275 error at all, however the unicode text is garbled.

Environment : Oracle database server and Oracle database client are both Oracle 11g

Beginning in 11g, Oracle practices stricter sanity check. Toad for Oracle 10.x and onwards is unicode compatible and data encoding with stricter sanity check causes this error.

WORKAROUND 1:
Install another Oracle client that is version 10g or lower, given a less strict sanity check in this version.

WORKAROUND 2:
Use Toad 10.x with Oracle 10g when querying an Oracle 11g table containing data of such nature.

WORKAROUND 3:
Refer to the solution on the Oracle website:
https://forums.oracle.com/forums/thread.jspa?threadID=914498

STATUS:
Enhancement request ST73046 has been submitted to Development for consideration in a future release Toad for Oracle.