I get the following error message:
Interface\AddOns\aux-addon\core\cache.lua: 178: attempt to index global `aux_item_ids' (a nil value)
The addon is unusable.
I tried disabling all other addons and deleting WDB folder.

Yes to both. I just downloaded it today from here.
Older version caused a different lua error.

also got an error after deleting the savedvariables, but a different one. fixed it now ...

I downloaded the newest version and the problem persisted (albeit with different error code) until I deleted all aux files from WTF folder.
Now works like a charm.
Many thanks for instant fix and keeping the awesome work!

Newest version? Client closed when deleting the folder?
edit: eh wait, WDB? addon savedvariables are in the WTF folder. (you don't need to delete the whole folder, just the aux file)