When I want to move a file to the Trash, Nautilus give me an message saying this:
You can't move example.file to the trash can. Do you want to remove it immediately?
I can give you this photo but it's in Spanish

When I want to move a file to the Trash, Nautilus give me an message saying this:
You can't move example.file to the trash can. Do you want to remove it immediately?
I can give you this photo but it's in Spanish

I had the same problem and found out that the trash had the wrong owner. So I deleted the trash folder and made a new one.
Steps:
cd ~/.local/sharels -ld Trashroot - delete the folder with: sudo rm -r Trashmkdir -m 700 TrashHope I could help and that it solved your problem, because it did for me.
As mentioned by kr4utz your problem is that Trash is owned by root.
A better way of changing the ownership without deleting the Trash folder would be to use the chown command from a terminal (Ctrl+Alt+T):
sudo chown -R "$USER" ~/.local/share/Trash
That will change the owner from root to yourself without deleting your Trash folder.
That's what worked for me, if the files that refuse to delete are on a partition which is not formatted as ext*:
Open /etc/fstab in any editor as root (e.g. using sudo nano /etc/fstab).
There add in the line of the partition you have problems the option uid=1000 (if your user ID is 1000, else change it)
Example:
/dev/sdb2 /media/scambio vfat rw,utf8,umask=0,uid=1000 0 0
and reboot
I found other solution that works for me. I had the folder Trash where the owner was root.
I delete the folder Trash like root user, you can do it directly from terminal with the correct command or like I did, I enter in the terminal the command:sudo nautilus, this open the nautilus like root user, I look for the folder Trash (.local/share/Trash) and I delete it (like root user) and after this I close the nautilus. I opened again the nautilus but like username (I mean normally), I delete some file and this automatically creates a folder Trash where the ownership now was my username.
Sorry for my english
I have tried all above solutions but they didn't worked for me. Then I just gave all the permissions to Trash folder and it worked. Follow the below steps-
Step 1: Open Terminal.
Step 2: Run the command- cd /home/username/.local/share
Note that you have to replace "username" with your username eg. for me it is- cd /home/willson/.local/share
Step 3: Give all the permissions to Trash folder using Command-
sudo chmod -R 700 Trash/
Now your deleted files will move to Trash.
For me, it was that partition was mounted in a folder owned by root and others didn't have write permissions
drwxr-xr-x 22 root root 4096 Sep 17 01:31 data
So the trash folder could not be created in the top folder
I just changed the permissions of the folder were the partition is mounted.... and voila, it worked!!!!
sudo chmod 777 data