Mint desktop empty: no icons & folders, no mouse actions

My desktop fails for one of the users (2) only:

No icons
No action upon right mouse button

(For user 2 all is fine. Users can be switched during session, then no issues for user 2. Back again to user 1: same problem again)

Only way to operate under user 1 is by general menu.

Any suggestions?

System: Kernel: 4.15.0-52-generic x86_64 bits: 64 compiler: gcc v: 7.3.0 Desktop: Cinnamon 4.0.10 dm: LightDM Distro: Linux Mint 19.1 Tessa base: Ubuntu 18.04 bionic