Error messages for sync problems

Below is a list of common error messages that you may come across in Google Drive when a file or document can't sync and some possible solutions.

Error message

Likely reason

Suggested steps

An unknown issue has occurred. Something unexpected has happened. Restart Google Drive. If you still see the message, please post in the Google Drive forum.
Authorization failure You no longer have permission to access this file. Contact the owner to check on / request access to the file.
Connection failure A connection to Google couldn't be established (often due to a proxy or a bad Internet connection). Click Retry All or restart Google Drive on your Mac/PC.
The Google Drive server encountered an error. You temporarily lost your connection to Google. Click Retry All. If this continues over several hours please post in the Google Drive forum.
This file is a link to an online Google document. It cannot be changed. You tried to alter a Google document from your desktop using a third party application. You can only change Google documents when online. If you see this error, make a copy of the original document online and select it for syncing.
The file on your computer is missing. You deleted or moved a file out of the Google Drive folder during the syncing process. Restart Google Drive on your desktop.
This file points to an invalid online Google document. The original Google document is no longer available online (e.g. your Google document was deleted while you were offline or paused a Google Drive sync). Remove the file from your Google Drive folder and restart the application.
You do not have enough Google storage for this file. Please buy more storage. A file's too large for the amount of storage you have left online. Purchase more storage or delete some of your files online. Learn more.
You do not have permission to sync this file. You have view-only permission for the file. Contact the owner for edit access to the file.
You only have permission to view this file, so your changes cannot be synced. You tried to edit and save a file to which you have view-only access Google Drive. Contact the owner of the document and request access to edit it.