I shut down my Mac every Friday night and when I go to open Acrobat Reader on Monday, all my files are gone, other than the Welcome PDF. Why is this happening? Do I have something toggled on that I don't want?
Sorry to hear about the trouble caused.
Looking at the scenario given above, it seems you are looking for the files stored in the Adobe Document cloud.
There's likely a chance that you are not signed into the application or used a different email address to Sign In than what was used before.
Check your email address once. Also, Sign In on Document Cloud web to see if you can locate your file here: https://acrobat.adobe.com/link/home/
Does this only happen at the weekend, or does it happen if you just reboot another time? Where do you save your PDF files?
In my line of work, I don't need to keep files for more than a month or so, so it's not a huge problem. I keep them on my desktop until I no longer need them, then move to trash. So I can retrieve either thru the sent file or from the trash. But to answer your question, it's after every time I shut down/reboot.
Here are some troubleshooting thoughts:
Let us know if any of this helps.