[This is a guess]
As "you" (i.e. not as root)

Uname=`id -nu`
Uno=`id -u`
echo "the id command says I am:   $Uname $Uno"

ls -l /run/user/$Uno

• is there a directory named /run/user/$Uno ???

• are the permissions at least "drwxr--r--" (744)

• if not, "sudo su" and make it so