Conversion Error!

Hi. 

I have been translating a document from English to Japanese

with TRADOS STUDIO 2017 Professional ver.

When I try to convert the file from SDLXLIFF → WORD file, the following error occurs:

"There is no tag '<bookmarkstart id = "5" name = "_bookmark4" />' in
segment 586 and 587. Please validate the tag and check the details."

The error is also not allowing me to display the preview. 

 

Any idea why?

Please help. Cheers.