Taegeun Yoon 

Please have a look at this KB article:
Message when opening (a file from) a package in Trados Studio: Dependency file not found (sdl.com)

If the file cannot be found at the path which is shown, you have to find the original source file that was used to create the bilingual file. You may have to ask the person who sent you the package.
Alternatively, you can skip the generation of the target file and only send back the bilingual file, leaving the target generation to the person who sent you the package. 
Ask the person who sent you the package to change the SDLXLIFF file option in their Studio for future packages.

Taegeun Yoon 

Please have a look at this KB article:
Message when opening (a file from) a package in Trados Studio: Dependency file not found (sdl.com)

If the file cannot be found at the path which is shown, you have to find the original source file that was used to create the bilingual file. You may have to ask the person who sent you the package.
Alternatively, you can skip the generation of the target file and only send back the bilingual file, leaving the target generation to the person who sent you the package. 
Ask the person who sent you the package to change the SDLXLIFF file option in their Studio for future packages.