can't erase redundant file from trash

I had several backups on external disks, including backups of 'Core Services'. To free up space I moved one backup to the trash. Now the (copy) of 'Core Services' is stuck there and can't be erased. What can I do? (I know nothing about code; barely know what the terminal.app is, let alone how to use it).

Reconnect the external drive, then try to empty the trash.

I have nothing windows on my mac, just mac stuff, and I always have antivirus/anti-malware programs running in the background. I'll check nonetheless, as soon as I get back to the office (tomorrow), where the mac in question is. And I'll try dis-/reconnecting the external hard-drive. I'll post the results. Thanks for the input.

antuttle said:

I have nothing windows on my mac, just mac stuff, and I always have antivirus/anti-malware programs running in the background. I'll check nonetheless, as soon as I get back to the office (tomorrow), where the mac in question is.

Click to expand...

Don't know what any of that has to do with the question above. Is there another question in there?

And I'll try dis-/reconnecting the external hard-drive. I'll post the results. Thanks for the input.

Click to expand...

If you delete files from an external drive; in order to empty the trash of those files, the external drive must be connected.

How embarrassingly simple. Duh. I disconnected the external drive, reconnected it, and the trash was empty. Thank you so much!