Managed file support

From the info you give me, I cant say whats wrong.

Make sure you have access to the files (test with user 1).

Try searching for something that will not return any files and see if you get results.
If you get results here, then its something with the file plugin.

Can you check the JSON response in Firebug or something else and see if you get any errors when files should be included in the search results?

This means that you dont have any errors and you clearly get results back.

What you also can do is to check the watchdog log and see if you find anything.

What browser and theme are you using? Try running some default theme like garland, bartik, or seven and see if that helps.
Also, clear the cache.

I'm having the same problem.
Tested under Chromium and Firefox.
Tried further to debug this.
The query-object is executed, but doesn't give any result.
This is the object which returns:

... (Object) EntityFieldQuery
  altered (Boolean) FALSE
  entityConditions (Array, 1 element)
    entity_type (Array, 2 elements)
      value (String, 4 characters ) file | (Callback) file();
      operator (NULL)
  fieldConditions (Array, 0 elements)
  fieldMetaConditions (Array, 0 elements)
  propertyConditions (Array, 2 elements)
    0 (Array, 3 elements)
      column (String, 6 characters ) status
      value (Integer) 1
      operator (NULL)
  1 (Array, 3 elements)
      column (String, 8 characters ) filename
      value (String, 6 characters ) %aanb%
      operator (String, 4 characters ) LIKE
  order (Array, 1 element)
    0 (Array, 3 elements)
      type (String, 8 characters ) property
      specifier (String, 8 characters ) filename
      direction (String, 3 characters ) ASC
  range (Array, 0 elements)
  pager (Array, 0 elements)
  deleted (Boolean) FALSE
  fields (Array, 0 elements)
  count (Boolean) FALSE
  age (String, 18 characters ) FIELD_LOAD_CURRENT
  tags (Array, 3 elements)
    linkit_entity_autocomplete (String, 26 characters ) linkit_entity_autocomplete
    linkit_file_autocomplete (String, 24 characters ) linkit_file_autocomplete
    file_access (String, 11 characters ) file_access
  metaData (Array, 0 elements)
  orderedResults (Array, 0 elements)
  executeCallback (String, 0 characters )

I found out, results are given.
It's the entity_acces call which causes the results to disappear.
linkit-plugin-entity.class.php line 192

 if (!entity_access('view', $this->plugin['entity_type'], $entity)) {
        continue;
 }

removes results. Since file_entity doesn't has a file access entity API (yet)
#1227706

I'm guessing your talking about Add a file entity access API - http://drupal.org/node/1227706
Is there a fix for this or do we have to apply the patch from http://drupal.org/node/1227706#comment-5934038

I am indeed referring to #1227706: Add a file entity access API.
Patch attached overrides access check for files. But could be a temporary fix.

I used media V1 and adressed this with file_create_url() (which isn't a very good solution either.
It should be solved in linkit. I think best would be to override BuildPath for the file-entity-plugin.

Confirm that the patch in #9 does get it to work - can locate media at least, but as mentioned by others, the link goes to the file entity which is not the wanted behavior.

Attached file fixes up the path so that it links to the actual file, and not the file entity.

Commited this patch. Seems to work.

I needed relative paths for file links. I've added an option 'Link to file using relative path' inside the fieldset 'Managed files plugin settings' on the linkit profile config page. Not sure if this is the best way to do it but it works.

What we really need is to suport something more portable. Ie, a filter that works using the fid, rather than any url to the file. The Portable Path module aims to do something like this, although currently fails in my opinion. However, there is a module on Github referenced in the ticket #1647980: Use fid rather than stream wrapper. which looks promising.