Hello Kimberlyl,
Sorry for the delayed response and inconvenience caused. As per the description above, when you are saving a PDF file and renaming it using Adobe Reader DC "Save As" function, it changes the file to a .tmp and this file cannot be edited or saved, Is that correct?
Are you trying to save a PDF form using Adobe Reader? What is the dot version of Adobe Reader installed? To identify, refer to Identify the product and its version for Acrobat and Reader DC
Have you tried renaming the .tmp file and adding the pdf extension to it? Highlight the .tmp file, right click>choose rename and add .pdf after the file name, for example: abc.tmp>abc.pdf(only for Windows).
Check for any pending updates of Adobe Reader from help>check for updates, reboot the machine after installing any updates and see if this brings any difference.
Also, repair the Adobe Reader from help>repair installation (only for Windows), reboot the machine and try saving the file again.
Have you tried with other PDF files or is it specific to one PDF file? Is it a Mac or Windows machine and what is the version of operating system installed?
Let us know how it goes and share your findings.
Regards,
Anand Sri.