This project is already opened by another software or instance of HelpNDoc. Please close the project first.


This means that this HelpNDoc projects can't be opened or saved because either:

  • Another instance of HelpNDoc has already opened this project without closing it
  • It is used by another software or anti-virus
  • It is marked as read-only or in a read-only folder
  • The Windows user doesn't have rights to read and/or write to that location


  • Try rebooting your computer to make sure that no process is using that file anymore
  • Make sure that only one instance of HelpNDoc has this project file opened
  • Make sure that no other software has this project file opened 
  • White-list that file or folder in your anti-virus software
  • Make sure that your Windows user has read / write access to that folder and project file
  • Try to move the project file to a local simpler path such as c:\doc\doc.hnd to see if that is working better