Please make sure that the PDF document you are reading is text, not pictures. At present, there is a dictionary that temporarily does not support word selection for picture documents.

You may not have closed Adobe Reader or Acrobat Professional during installation or update. Please close Adobe Reader or Acrobat Professional, restart Youdao Dictionary and try again.

If you are using Acrobat Professional, please check your task manager (Ctrl+Alt+Delete to start the task manager), find a process named Autotray.exe in the process box, and restart the Youdao dictionary after completing the process; Or you can manually copy the YodaoDict.api file (default is C:\ Program Files \ youdoor \ Dict) in the installation directory of Youdao Dictionary to the plug_ins folder in the installation directory of Acrobat.

If you are a restricted user with non-administrator rights, please log in to windows with an administrator account and start the Youdao Dictionary once, or you can manually copy the YodaoDict.api file (default is C:\Program Files\Youdao\Dict) in the Youdao Dictionary installation directory to the plug_ins folder in the Acrobat installation directory.