I have upgradeded from Kubuntu 15.04 to 15.10 yesteday and got the same error.
For me this looks like a shell script error. E.g.:
HOME=$(some | invalid | command | sequence) KWALLET_CONF="/$HOME/.config/kwalletd5rc" # results into ""//.config/kwalletd5rc"
I also made an investigation about which process spawns the message: elvenfighter ~ $ ps -eo pid,ppid,args | grep -i kwallet 1196 1174 [kwalletd] <defunct> 1197 1174 /usr/bin/kwalletd5 --pam-login 17 21 1788 1197 /usr/bin/kdialog --title kwalletd5 --msgbox Configuration file "//.config/kwalletd5rc" not writable. Please contact your system administrator. 1793 1 /usr/bin/kwalletd --pam-login 17 20 2489 2442 grep --color=auto -i kwallet
elvenfighter ~ $ ps -o pid,ppid,args -p 1174 PID PPID COMMAND 1174 1022 /usr/lib/x86_64-linux-gnu/sddm/sddm-helper --socket /tmp/sddm-auth950d1696-1757-4438-91c7-c06607824e4e --id 1 --start /usr/
I have upgradeded from Kubuntu 15.04 to 15.10 yesteday and got the same error.
For me this looks like a shell script error. E.g.:
HOME=$(some | invalid | command | sequence) CONF="/ $HOME/. config/ kwalletd5rc" # results into ""//.config/ kwalletd5rc"
KWALLET_
I also made an investigation about which process spawns the message: kwalletd5rc" not writable. Please contact your system administrator.
elvenfighter ~ $ ps -eo pid,ppid,args | grep -i kwallet
1196 1174 [kwalletd] <defunct>
1197 1174 /usr/bin/kwalletd5 --pam-login 17 21
1788 1197 /usr/bin/kdialog --title kwalletd5 --msgbox Configuration file "//.config/
1793 1 /usr/bin/kwalletd --pam-login 17 20
2489 2442 grep --color=auto -i kwallet
elvenfighter ~ $ ps -o pid,ppid,args -p 1174 x86_64- linux-gnu/ sddm/sddm- helper --socket /tmp/sddm- auth950d1696- 1757-4438- 91c7-c06607824e 4e --id 1 --start /usr/
PID PPID COMMAND
1174 1022 /usr/lib/