Today i established my guild successfully and once i tried to promote some members to a higher rank i received errors that i need to disable aux addon every time i pressed the up arrow of promotion.

Someone else has reported that too. No idea what the connection could be but I'll try to fix it this weekend when I'm back home.

Do you have any more information? Is there a lua error (/console scriptErrors 1 if you haven't enabled them yet)? I can't find any connection to aux from looking at the code.

this should help:
Questie/Questie#697
(from https://us.forums.blizzard.com/en/wow/t/guild-master-cant-edit-guild-permissions/277494/4 )

Thanks a lot. Could you check if it's working with the newest version please? (github not curse)

still getting

1x [ADDON_ACTION_FORBIDDEN] AddOn 'aux-addon' tried to call the protected function 'GuildDemote()'.
!BugGrabber\BugGrabber.lua:519: in function <!BugGrabber\BugGrabber.lua:519>
[C]: in function `GuildDemote'
[string "*:OnClick"]:1: in function <[string "*:OnClick"]:1>

What about now? And if it's still not working, could you please try commenting out everything in core/shortcut.lua and check if that fixes it?