Desktop cann't work in sometimes

Hello admin,
I’m using KIT Nvidia Jetson TX2 on Ubuntu16.04 with a desktop.
last week, my desktop lost taskbar tool, can not open terminal…
after I try recover but not success and this program work return. I do work normal. But today this problem is apperance again.
I cann’t open terminal and lost taskbar tool.
HOw to I fix this error. Please help me.
Thank you very much!

You may try to delete compiz cache.
After boot when Ubuntu GUI login screen appears, go to a virtual console (Ctrl-Alt-F2), log in and launch:

sudo rm -r /home/<your_user>/.cache/compizconfig-1

Then switch back to X (Ctrl-Alt-F7) and try to log in.

If this doesn’t work, check also that your user belongs to group video: