File transfer to smart phone not working

[Sigurd]

Hi,
As usual I tried to transfer a pdf-file from my computer to my smartphone Lenovo K6 using Dolphin. Never before I had a problem. But now with Kubuntu 17.10 I always get the message "Access denied. Could not write to" or at most times "/Lenovo K6 is a file, but a folder was expected". What is this? What can I do to transfer to file?
Kind regards,
Sigurd

[whatthefunk]

Is your phone an iPhone or Android? If you use Android, consider using KDE Connect. Link: https://community.kde.org/KDEConnect

[NickStone]

Make sure your phone is set up for file transfer when connected to PC. Also make sure phone is mounted (just like a drive) and you should be able to use it just like a USB storage device.

[Sigurd]

Hi whatthefunk and NickStone,
A Lenovo K6 is an Android smartphone. It runs with Android 7. I did install KDE connect on my smartphone too. It looks like I can transfer files from the smartphone to the computer but not the opposite direction. But this is what I want to do.
Before I have installed Kubuntu 17.10 I simple used Dolphin to do the file transfer from the computer to the smartphone without any problem. Dolphin did recognize the smartphone and its drives and listed it. And I could do the copy of files. Now Dolphin still is listing the drives of the smartphone. But if I try to do a file copy from computer hard drive to the cell phone I will get the above mentioned messages. What is the difference in Kubuntu 17.10 that here Dolphin is no longer able to do such a file copy from my computer hard drive to my cell phone?
Kind regards,
Sigurd

[Sigurd]

Hi,
I found a solution: PCManFM file manager can do it without any problem (as Dolphin did before). What is wrong with Dolphin in Kubuntu 17.10 that it is uable to do such a simple job. And it could do it before.
Kind regards,
Sigurd

[id5.1]

Just for information, I can copy files into my Android phone through Dolphin, so it's not universal.