Finder suddenly asking for permission to move to trash

Solution 1:

Troubleshooting: There are a wide variety of things that might cause a problem like this, so the first thing to do is to try to figure out what's causing it in your particular case. And a good first step in troubleshooting is to try to isolate the source of the problem by changing things, and seeing which affect the problem. For instance, does it happen with all files, or only some files (or files in certain folders, or on certain volumes, etc). Create files and/or folders in various places, and try throwing them out. If it happens with only certain files or folders or whatever, it's probably something about those particular files/folders, and you should concentrate on them; if it happens everywhere, it's more likely a general problem (e.g. something with your .Trash folder.)

(Note: macOS keeps a separate trash folder on each volume -- because you can't put a file that's physically on one volume into a folder (including a trash folder) on a different volume. On the volume where your home folder is, it's ~/.Trash; on other volumes, it's /Volumes/volumename/.Trashes/$UID, where $UID is your user ID number, usually 501.)

Once you've got an idea where the problem's coming from, you can get more info about file/folder permissions with ls -leO@ (or ls -leO@d to see a folder's permissions, rather than its contents). Here's an example on my Mac:

$ ls -leO@d ~/.Trash ~/Desktop
drwx------  75 gordon  staff  - 2550 Sep  5 02:03 /Users/gordon/.Trash
drwx------@ 62 gordon  staff  - 2108 Aug 31 00:59 /Users/gordon/Desktop
    com.apple.FinderInfo      32 
 0: group:everyone deny delete

I won't go into detail here, but the rwx------ bit is the regular unix permissions; gordon staff is the owner and group; the - after that is flags (- means none; uchg means it's locked) the com.apple.FinderInfo line is an extended attribute, and the 0: group:everyone deny delete is an access control entry.

(The deny delete access control is normal here, it's just to keep people from deleting their Desktop folder by mistake. It only applies to the Desktop folder itself, not its contents. Well, unless it had an inherit attribute, but it doesn't.)

In this case, it looks like the permissions are messed up on a specific folder:

...
dr-xr-xr-x@ 116 shane  staff  - 3712 Sep  3 17:47 /Users/shane/Music/Folder_2/
    com.apple.macl    72 
    com.apple.quarantine      57 

That dr-x at the beginning means it's a directory (aka folder), and the owner (shane) has Read and eXecute (actually search... long story) permissions, but not Write. Write access on a folder controls making changes to its contents: creating/moving files, renaming files, and deleting files. You should almost always have write access to your own stuff.

Fortunately, it's easy to add write access:

chmod u+w /Users/shane/Music/Folder_2/

The u+w bit here means "for the user (i.e. the owner), add write access".

I have no idea what would've caused those weird permissions in the first place, but hopefully that's the only problem and this'll solve it.