Steam failure due to SDDM breeze theme

I installed KDE on Arch linux and as suggested I used SDDM with breeze theme. However, it seems breeze is causing issues and it is better to switch back to the default theme.

I had noticed something was off when I first logged in via SDDM. After login, the login screen did not go away; it just stayed as an app with a title bar and I could minimise it. I did not think much about it at that time.

I installed steam and it started fine. The next day when I started steam, it failed. I tried to start it from command line and I got the following error.

/home/dknight/.local/share/Steam/steam.sh: line 161: VERSION_ID: 

unbound variable
/home/dknight/.local/share/Steam/steam.sh: line 161: VERSION_ID: 

unbound variable
Running Steam on arch  64-bit
/home/dknight/.local/share/Steam/steam.sh: line 161: VERSION_ID: 

unbound variable
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/

version(1454620878)
libGL error: failed to open drm device: Permission denied
libGL error: failed to load driver: i965

libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast

I was not sure how to fix it so I jumped on to #archlinux channel on Freenode. A user by the handle Namarrgon took interest in my issue. During the course of discussion, I found out that there were a lot of errors with the X session. Upon his suggestion, I ran the following command.

loginctl show-session $XDG_SESSION_ID -p Active -p Remote -p Active

The output is as follows:

Remote=no
Active=no

This rang a bell as it meant the session wasn't considered active and as a result the right acl weren't set which in turn didn't allow access to /dev/dri/card0. Namarrgon suggested to log out and try using startx to start the X session. When I got a hint that loading X was might be the issue, I remembered that SDDM loads it and it was having issues. So,it might be because of SDDM. Looking at dmesg output I found the following line.

[   61.033982] sddm-greeter[360]: segfault at 30 ip 00007f67673d89bf 

sp 00007ffdb3a81180 error 4 in libKF5CoreAddons.so.5.18.0

[7f67673a4000+96000]

Upon seeing this Namarrgon, pointed out to a bug which attributed the SDDM issue to breeze theme.