The company I work for uses Acrobat Reader DC on Windows 10. Since the change we are having problems with the file extension for (capital) .PDF running with one of our other computer systems. My question is there a way to automatically change the file extension from (capital) .PDF to (lowercase) .pdf ? Like a setting. We have to manually save as .pdf. Example 1234567.PDF need to change to 1234567.pdf. Please help.
There's no such feature in Reader. You should contact the developers of this application you're using and ask them to fix it. It should not be an issue.
Just ran into this issue so I thought I would share. I was running into this .PDF issue when the file was opened via Reader or Acrobat in Chrome. I saved the file and opened it using the desktop app and resaved it. When resaving it I was able to confirm it was saving as .pdf not .PDF. I double checked in the properties of both files and the old one is still .PDF but my new one is .pdf.