i think you have same issue with other peoples, who cant launch wazapp.
try to register new account with wazapp.im version and then install and use old nightly8
I have a problem with avatars.. if I push reload button on the right top corner, wazapp doesn't donwload avatars in nightly9, while in nightly8 did.
Another thing: "Update status" in people's profiles, in all recent nightlys, remains green (so selected) and, if I push another button, the button itself desappears..