These error messages can appear if you are storing your files on the Zotero server. What it means is that the file for the attachment that you are viewing has not been uploaded to Zotero. You should start by checking the Zotero troubleshooting instructions.
Some of the common causes of this problem include:
- You may have exceeded your storage quota
- Zotero has not been synchronized with the server or file synchronization is turned off
- If you are using a group library, file storage may be disabled for that group
The first troubleshooting step that you can take is to verify that you are not over quota. This can be done on this page https://www.zotero.org/settings/storage
. If you have exceeded your quota, you need to subscribe to a larger storage plan or delete some attachments. Alternatively, you can use WebDAV or Dropbox
. If you are using a group library, you need to ask the group owner about the quota. If you are not over quota, then you need to synchronize Zotero. If this did not help, check that you can access the file on the Zotero on your computer. If you can access the file, you should restore your library to server
If you want to verify that the file does not exists on the Zotero server, use the action button in ZotPad and then choose "Lookup" and then "Zotero online library". This will open the attachment page on the Zotero website in Mobile Safari and you can verify if the file exists on the Zotero server.