Many times, when I tried to empty the trash, I got the same alerts as you. Sometimes, I lacked the proper permission, the file was otherwise locked, or whatever.
Regardless, once the file was in the trash and I clicked on Permanent Eraser, it always got deleted.
Perhaps there is an exception somewhere, but I have yet to experience that.
Harv 27" i7 iMac (10.13.6), iPhone Xs Max (12.1)
Those who can make you believe absurdities can make you commit atrocities. ~Voltaire
