issues when connecting to my phone

[davehu]

I often plug my phone via USB into my desktop to transfer pictures to my desktop system. No problems. However if I try to preview the picture directly from the phone, I get a "the directory name is invalid" message. Also even though I can copy pictures FROM the phone TO the computer, I am unable to copy files FROM my desktop back to the phone. Of course Win 10 file explorer has no problems. The phone is an android.