Error when combining files

Hi, I always combine files for work. I have been doing it for the past year in the Adobe app on my phone. I tried to combine files today and I keep getting an error message. It's the same kind of files, there's literally nothing different about what I'm trying to do today. I've restarted my phone. Deleted and reinstalled. Tried Adobe on my computer instead. None of it is working. Please help me!!!