run-time error '53'

That is an Adobe add-in which may be u=in the location indicated by Ivan B but the location can vary based on specific macOS & Office version. If that path doesn't exist on your Mac or the MacPDFM file is not there contact Adobe Support – It's their product so they can point you to the right location based on your specs.

Hi,

Here's the solution, following John Korchok and Jonri's:

Close Word

1. While holding down the Option key, click on the Go menu in the macOS menu bar and choose Library. Your hidden user Library folder opens.
2. Open ~/Library/Group Containers/UBF8T346G9.Office/User Content/Startup/Word.
3. Open ~/Library/Application Support/Microsoft/Office365/User Content/Startup/Word/

(and /Powerpoint instead of /Word if the problem appear with PPT)

1. Deleting the linkCreation.dotm in the Word folder and the SaveAsAdobePDF.ppam
2. Restart your computer. Open Word and check that the message does not appear

The problem occurs due to the Adobe Acorbat plugin causing this error.

Please consider rating the question (accept the answer or not), and access the community at Microsoft Q&A if you have further questions.

Credits.: https://learn.microsoft.com/en-us/answers/questions/1007772/run-time-error-53-word-for-mac?page=1#answers

Thanks