Why did redundant letters show up in the generated target file, while the bilingual file looks good and does not contain these additional letters?

Question

I have created a project to translate a simple docx file, with target language of French and Spanish. 
 It is weird that some redundant letters of the first word displayed in the generated target Spanish file. While everything looks good in the bilingual files in trados studio editor. And it looks good in the exported bilingual docx file for external review. For French file, it does not have the same error. 
 The source sentence is: Thank you for .... 
 The Spanish translation displayed in Trados Studio Editor is: Gracias por .... while became "GraciGracias por" in the generated target file. 
 Here I uploaded the problematic file. It is highly appreciated if you could help investigate the root cause. 
 file_and_screenshot.zip

Paul · Answer

Hi Sara Qin 
 
That is very strange. Can you tell me how you processed the file to get to this point? Did you simply tranlsate the source file yourself and save the target? Can I see the original source file?

Paul · Answer

Hi Sara Qin 
 
Can you tell me what version of Studio you are using? This was apparently a bug in an older version that could arise when you start typing very fast after opening a document. The content was added before the first segment which you can see if you filter on "All Content" as opposed to "All Segments" in the display filter. It was resolved so I'm wondering what version of Studio you are using?

Trados Studio > 1. Trados Studio

Why did redundant letters show up in the generated target file, while the bilingual file looks good and does not contain these additional letters?