Getting an error message when trying to combine two PDF files into one PDF file?

[#1]

When I select multiple PDF files and try to combine them into one document, I get a message that says "One or more files selected for Combine could not be deleted from the source folder.  You can delete these manually from the folder."

Adobe Acrobat Pro DC version 2022.001.20085 (64-bit version)

[BarlaeDC]

Hi,

Is there a question? just curious as to what is expected from this post?

[#3]

This is an error that I am receiving.  I would like to know why I am receiving it and also how to stop receiving it.