Problems updating KDE Plasma Mobile OS

[IMSAI8080]

Hello,
I'm experiencing problems updating my OS (KDE Plasma Mobile).
I'm using a SD Verbatim 32 GB (just KDE Plasma Mobile on it).
On the terminal, after:

$ sudo pacman -Suuyyw

got this message:

error: failed to update mobile (unable to lock database)
error: failed to update core (unable to lock database)
error: failed to update extra (unable to lock database)
error: failed to update community (unable to lock database)
error: failed to synchronize all databases

Also, tapping on Discover, on the bottom of the screen, when the application starts, I got:

unable to lock database

Any help?

Many thanks.