I don't have permissions to open my files?
This post fixed my TextEdit permission problem:

https://www.cnet.com/news/fix-permissions-errors-for-sandboxed-applications-in-os-x/

I quit TextEdit, manually cd'd to ~/Library/Containers, and moved 
com.apple.TextEdit to my home directory out of the way, then restarted
TextEdit, and I was able to open files for which I was previously getting
permission errors.