You can try replacing the source~

checkout your mirror list

Hello If you have Difficulty to Update Deepin Version. Please Make sure that you have default setting  Shown In Picture

I have updated to 15.7 on two machines and it has broken both. Also a fresh install doesn't seem to fix it. Dock keeps crashing, startmenu hangs and the network connections come and go. Is nobody else experiencing this?

Edited by danygee at 2018-8-27 11:15

Yes, version 15.7 brakes lots of different things on different hosts.
On my desktop (i7-6700, GTX1080, ASUS Z170 Deluxe Motherboard) setting custom wallpaper does not blur the background on login screen and in fullscreen menu.
Window control buttons don't scale properly in 4K resolution anymore for non system apps (they are blurred).
Telegram is launching long due to fontconfig loop.
Conky stopped to render bold fonts properly.

you can use

sudo apt-get update

sudo  apt-get upgrade

thank you!