when in champ select, and you cant create your own pages yet, you can select between the 4 available runes (domination, prec. etc). you select one of those. when the picking time has finished and we come to the last 10 seconds of champ select, the runes will automatically switch to something else, for no good reason.
this is in low level, i havent unlocked custom runes yet
EDIT: Ok I just started another match, and it just read "runes now unlocked". but the runes were already unlocked the whole time, the 4 available ones that is. I still am not able to create pages. the message was obsolete, there was nothing unlocked in addition to what i already had before. but the bug is gone. the selection now remains and doesn't change anymore.