NVivo for Mac project did not close successfully (error and solution)

I am using NVivo Mac and receiving the below error message

This project did not close successfully the last time it was open. Please restart your computer and try opening it again. If this problem persists, please contact Support.

Answer

If you have restarted your computer and the issue persists, please follow the steps below:

1. After restarting your computer, ensure NVivo is closed
2. Open Finder and navigate to the location of your project file (nvpx file)
3. Right-click on the project file > Get Info and untick Lock (if ticked)
4. Copy your project file (nvpx file) to your Desktop or to another different folder and rename it. For example, rename Myproject.nvpx to Myproject_new.nvpx. 
5. Also ensure the project name is not in all capital letters and/or the project file name doesn’t contain a space at the end of the filename, for example MYPROJECT .nvpx. If yes, please remove the space, rename the file and add lowercase letters to file name.
6. Double click on the project to see if you are able to open it.

Note: If you use Dropbox or other cloud storage services such as Google Drive, OneDrive etc. to store and use your project file(s), ensure that active synching is disabled whenever using the file in NVivo. If active synching is used whilst using your project file, this may cause project corruption such as "Failed to Open Project. This project did not close successfully the last time it was open" error.

If the issue persists after you have tried the above steps, you may also be able to resolve the issue by converting the project to NVivo Windows format and then converting it back to NVivo Mac format. More information about this is found in Can I work with my NVivo project on Mac and Windows or convert project?