In File Explorer, files that are not in the local cache will have a grey X in their icon.  Normally, the CacheDrive will automatically download the file from the cloud when the file is accessed and the grey X will disappear.


However, there may be some instances where the file cannot be downloaded from the cloud and the file contents will not be available.  In some cases, the application may say that the file is corrupted or inaccessible.  Some possible reasons for this are:


  1. Internet access is down.
  2. The cloud storage service (Wasabi, Amazon S3, etc.) may be down.
  3. Cache may be filled with files that cannot be cached out.  This includes files that for some reason could not be uploaded to the cloud.


Reasons #1 and #2 above are generally out of our control.  For #3, check the amount of Writable Cache Space reported in MCM:



Writable Cache Space is the sum of Unused Cache Space and the space used by files that can be cached out.  If the Writable Cache Space is low, it's very possible that #3 above is the cause of the issue.


Low Writable Cache Space have several causes, two of which are:

  1. Replicate shares that have not been synced.  Since these files have not been uploaded to the cloud, the local versions of these files are the only ones available and cannot be deleted without data loss.  Run a sync of the replicate share to enable the device to cache-out these files.
  2. Files on the sync exclusion list consuming a lot of space.  This is an unusual condition, but is possible, for example, if large backup files are saved using the .bak extension.  Microsoft recommends using the .bak extension for SQL Server backups, so frequent database backups to the CacheDrive may consume a large amount of storage.  To remedy this situation, add change the sync exclusion list to allow sync of files with this extension or write the files with a different extension.

    To change the sync exclusion list, see the following article:

    How do I change what type of files to sync to the cloud?