How to Resolve Border and Background text boxes string is not showing correctly on Japanese OS

In the Letter in RTF message template, the Border and Background window is showing garbage texts for the test boxes labels in Japanese language mode.
User-added image

 This is identified as BUG in Portrait Dialogue Version 6.0 SP1.

A TFS is raised for this issue and the TFS number is: 33552.
UPDATED:  September 27, 2017