Last modified: 2013-04-16 08:53:12 UTC
Currently the attachment button inserts attachments like images, it would be more intuitive for it to just insert a link (attach, not embed).
According to one of its developer (Mark), Uniwiki extensions for MediaWiki are not under active development anymore "and it is safe to declare them obsolete/wontfix."
It is unlikely that there will be any further active development.
Closing this report as WONTFIX as part of Bugzilla Housekeeping and adding the whitespace entry "extension[unmaintained]". Please feel free to reopen this bug report in the future if anyone takes the responsibility for active development again.