Need help setting up Edimax EW-7811UTC Network adapter

[Nachlese]

@Lenny_1

Error: Failed to prepare transaction: could not find database

having no database cannot be good
so:

I copy/pasted and searched for that error message
and this came up:

Getting "Error: Failed to prepare transaction: could not find database" while trying to install icaclient package

I executed sudo pacman -Syy and then repeated the above command. This time the install has gone ahead without issues.

The essence is:
what happens after you have run:
sudo pacman -Syy
or
sudo pacman -Syyu
and then tried again … ?