WackoWiki

View source for Re: Cannot refer to uploaded files

So it uploads the file but it did not write the corresponding data in the file table.
The WackoFormatter parses then the ##file:## link and can't find the corresponding record in the file table.
Did you upgrade or downgrade the wiki? Please check if the file table has no missing or changed fields, this can happen if you changed the version without using the installer. The SQL script probably fails to insert the file record due to DB structure discrepancies. 

Please check the file table against the ((/Dev/Database/Layout/files file table schema)) for your version.

Fix the DB structure discrepancies by hand or run a fresh install with the version you want use. Additionally you can turn on the debug option, so it will show you all failed SQL queries in the footer, look out for ##-1##.

https://github.com/WackoWiki/wackowiki/blob/master/src/handler/page/upload.php#L267 (Example for WackoWiki 6.1)