Run-Time Error '53':

On Mac devices, this error popups up because Endnote has missing Windows components. Endnote is part of Microsoft Office. 

To resolve, please follow the instructions below:

1. Close all Office applications
2. Go to /Users/your-user-name-here/Library/Group Containers/UBF8T346G9.Office/User Content/Startup/Word
   • If the Library folder is initially hidden, press the “Command” + “Shift” + “.” (period) keys at the same time to display it.
3. Remove linkCreation.dotm
4. Restart Word and problem solved

1. Remove the SaveAsAdobePDF.ppam and SaveAsAdobePDF.xlam from the PowerPoint and Excel folders next to the Word folder.
2. Launch Excel and PowerPoint and go to the menu Tools -> Excel Add-ins... and Tools -> PowerPoint Add-ins..., respectively, and remove the Save as Adobe PDF add-in, by unckecking it and removing it with the "-" button and then click OK.
3. Restart Excel and PowerPoint and the problem should go away. If not, try several times to remove those options from the Tools menu.