I realize this has already been sort of asked, but the question I found was related to fonts rather than Synaptic in general.

Every time I run anything in Synaptic, everything installs perfectly fine but then I receive this error:

W: Can't drop privileges for downloading as file
'/root/.synaptic/tmp//tmp_sh' couldn't be accessed by user '_apt'. -
pkgAcquire::Run (13: Permission denied)

I'm not certain how this is fixed, especially since I neither have a user named _apt nor do I have any files at all in /root/.synaptic/tmp/.

Even though this error does not seem to effect anything, I'd still like to fix it just in case it actually is doing something I'm not seeing behind the scenes.