How do I install sandbox module 'Filedepot multiupload'?
The link you provided for the sandbox module 'Filedepot Multiupload' is actually an issue (request) for Drupal.org Project Applications.
The actual sandbox project is located at https://www.drupal.org/sandbox/e.ruiter/2290395 . On that page, wihin resources, there isn't any link mentioned (yet) with title &quot;Read documentation&quot;, which typically points to either available &quot;Community documentation&quot;, or to the &quot;Readme.txt&quot; that comes with the module.
The module's Readme.txt appears to be the best documentation currently available. To review/browse it, you have 2 options:

Browse the module's source code that you downloaded, which should contain that readme.txt.

Follow the &quot;Browse code repository&quot; on the project page of the sandbox project. Next visit the &quot;Tree&quot; tab and click on the Readme.txt link there.


Here is the content of that readme.txt:


Introduction: This module extends the filedepot module with multiple upload support. Files can be uploaded with the plupload module which supports drag and drop.

Installation: Just install the module by copying the module to site/all/modules directory or install with drush. If you get some errors about files missing and plupload is not loading, you are probably missing the plupload library. Find the README file of the plupload module and follow the instructions.



Note: while you're reviewing the Readme.txt and experimenting / testing that module, consider either (or both) of these approaches:

enhance the readme.txt with anything you learn/discover about it, and then contribute an updated version of readme.txt back to this sandbox project. E.g. by creating a documentation issue, and attaching a copy of the updated readme.txt.

create a community page containing such documentation, and then create a documentation issue for this sandbox project, requesting the module owner to update the project page to point to this new community documentation.