When performing any action on a PDF form, the following message may appear:
At the top of the form, in yellow, click on the "Options" drop-down:
Either of the two options (consider the document trusted once or always) will allow the PDF to be processed.
The tool will ask to save the PDF again when selecting one of the two options. It will close and reopen again, and if we now run the process that previously gave an error again it will work.