Upgrade StorageEPUB linked file not loading in internal reader — NetworkError (macOS, ZotMoov)
I'm unable to open EPUB files in Zotero's internal reader when they are stored as linked files (via ZotMoov) on iCloud Drive. The reader tab opens but displays a blank white screen.
**Environment**
- Zotero 9.0.1 (ARM64)
- macOS 15.7.4 (Sequoia)
- MacBook Pro M3 Pro
- ZotMoov 1.2.28
- EPUB stored as linked file in: ~/Library/Mobile Documents/com~apple~CloudDocs/Zotero Library/
- File is fully downloaded locally (not an iCloud placeholder)
Debug ID: D2120913777
**What happens**
The log shows repeated errors:
```
ReaderTab "[title]": TypeError: NetworkError when attempting to fetch resource.
```
Zotero correctly identifies the file as application/epub+zip and attempts to open it in the internal reader, but the fetch fails. The file is physically present on disk.
**What works**
- Same EPUB opens fine in external readers (Calibre, etc.)
- PDF linked files open correctly in Zotero's internal reader
- EPUB stored files (in Zotero storage) open correctly
**Root cause hypothesis**
The internal EPUB reader appears to use a network fetch mechanism that fails when the file path resolves outside of Zotero's storage directory (e.g. iCloud Drive path). PDF linked files seem to handle this differently.
**Workflow context**
I use ZotMoov to store files in iCloud so my Kobo e-reader can access them. Disabling ZotMoov or copying EPUBs into Zotero storage fixes the issue but breaks the e-reader workflow.
**Environment**
- Zotero 9.0.1 (ARM64)
- macOS 15.7.4 (Sequoia)
- MacBook Pro M3 Pro
- ZotMoov 1.2.28
- EPUB stored as linked file in: ~/Library/Mobile Documents/com~apple~CloudDocs/Zotero Library/
- File is fully downloaded locally (not an iCloud placeholder)
Debug ID: D2120913777
**What happens**
The log shows repeated errors:
```
ReaderTab "[title]": TypeError: NetworkError when attempting to fetch resource.
```
Zotero correctly identifies the file as application/epub+zip and attempts to open it in the internal reader, but the fetch fails. The file is physically present on disk.
**What works**
- Same EPUB opens fine in external readers (Calibre, etc.)
- PDF linked files open correctly in Zotero's internal reader
- EPUB stored files (in Zotero storage) open correctly
**Root cause hypothesis**
The internal EPUB reader appears to use a network fetch mechanism that fails when the file path resolves outside of Zotero's storage directory (e.g. iCloud Drive path). PDF linked files seem to handle this differently.
**Workflow context**
I use ZotMoov to store files in iCloud so my Kobo e-reader can access them. Disabling ZotMoov or copying EPUBs into Zotero storage fixes the issue but breaks the e-reader workflow.