Delete Images from disk error message "file named xxxxxx.jpg could not be moved to the trash folder

[DdeGannes]

I am trying to delete some old images from the Library Module grid view. I select the image and hit the "delete" key and the regular window pops up I then choose Delete from the disk. The following message is displayed.

I can go to Finder and use the option "Get Info" and the image shows as protected and I can deselect the protection.

Is there any option available in Lightroom to undo the protection? 

[TheDigitalDog]

Reboot in Safe mode and try deleting. Reboot with Shift Key. 

Or

Try Terminal and enter:
chflags -R nouchg DIRECTORY_NAME(where the DIRECTORY_NAME is the path to the parent folder.

[DdeGannes]

I think you have lost me here.

I can use the option to remove from the LrC Catalog but not the disk.

When I go to Finder I can locate the file and change the protection in the Info dialog. Then go back to LrC and delete from disk. That is what I would like to avoid.

[DdeGannes]

Ok I should have said "Locked" not "Protected".