There've been a few other reports of that. Could you generate debug output for the sync attempt from the Advanced pane of the Zotero prefs, submit it to the server, and post the Debug ID here? Thanks.

Any news on that? Can't get sync to work at all, at the moment...

I haven't tried to reproduce this yet, but you might try removing 2HGHQVF2.zip and 2HGHQVF2.prop from your WebDAV server to see if that fixes the problem. You'd need to do a Reset File Sync History on the other computer to sync that file back up.

What exactly led you to the assumption that this file is corrupt (or causing this error for some other reason)?

(3)(+0000000): Finished download of D:\My Documents\zotero\tmp\2HGHQVF2.zip.tmp

(2)(+0000000): 2HGHQVF2.zip.tmp is not a valid ZIP file

Can you provide another Debug ID?

As the beta7 changelog says, it's fixed now in terms that you can verify those URLs; but you can't put them into the box, it always gets cut to the base URL.

What's the actual problem you're having? The /zotero is hard-coded into the form and the code. You should only need to use about:config if the remote path is actually /zotero/zotero.

Can you send one or two of the ZIP files to support@zot....org, with a link to this thread? Thanks.

Also, in case you used Firefox to download them, it's worth trying a separate browser/program as well.

Well, I'm not sure how this happened—possibly some sort of network glitch—but you might as well delete all the files on the WebDAV server, do a Reset File Sync History from the Sync->Reset pane of the Zotero prefs, and try uploading again.

Well that's a new one.

To see if this is a local problem or a network/WebDAV problem, delete a few of the larger files from the WebDAV server, reset file sync history again, open up the 'tmp' directory within the data directory, and, after starting a sync, copy (don't move) any zip files that appear in the directory to another folder. You'll want to wait until the file size stops increasing. (The reason to pick larger files is that it should give you more time to copy them before uploading is complete and they're deleted.)

Then see if those copied files are also corrupt.

Ok... I have to admit... I don't get it :-(
I don't get what you're trying to achieve.

Well, I said above: to see if this is a local problem (e.g., a problem with zipping or writing to the disk) or a network/WebDAV problem (e.g., connections being closed prematurely, data being corrupted in transit). If the files aren't corrupted before uploading, it's the latter (which seems much more likely).

If uploading is too quick, try this:

1) Do the steps you did above to delete a few large files and clear file sync history. Don't sync yet.

2) Create a directory on your desktop called 'zoterozips'.

3) Open your Zotero data directory in a Finder window. If the 'tmp' folder doesn't yet exist because you've recently restarted Zotero, create it.

4) Open a Terminal window. Type bash and hit Return.

5) Drag the 'tmp' folder from the Finder to the Terminal window. It should paste the full filesystem path of the folder to the command line with spaces preceded by backslashes. Hit Ctrl-c.

6) Type/paste the following all on a single new Terminal line:

while true; do cp -v /path/to/tmp/folder/* ~/Desktop/zoterozips/ 2>/dev/null; sleep .1s; done

The /path/to/tmp/folder/* should be the path that was automatically pasted in above followed by a slash (if not there already) and an asterisk. If you're using the default data directory location, it should be something like /Users/dan/Library/Application\ Support/Firefox/Profiles/a5f2h5a6.default/zotero/tmp/*

7) Hit Return, and then begin a sync. If everything worked properly, you should see some ZIP files appear in the zoterozips file on your desktop.

8) When the sync is done, press Ctrl-c in the Terminal.

Then test the ZIP files and see if they're corrupt.

Can you provide a Report ID from Report Errors from the Mac, after trying a sync that involves uploading a ZIP? Also be sure to try disabling all other Firefox extensions.

Anything else unique about that Mac's setup? Is the Zotero data directory on a local, external, or network drive?

My best guess is that it's something with the network storage. Would you be able to temporarily switch the data directory to somewhere on the local hard drive, copy your files over, and see if the problem goes away?

USB flash drive?

Am I the only one who has encountered this problem?
Any idea how to fix this?

Zotero is great, I love it, but since everyone at our chair is using the networked home folder, no one can upload any new files. So I can only add new files from my Windows PC (or an USB stick as workaround which is akward and annoying since Firefox restart and moving the DB takes like forever).

The network administrator is kinda busy, I haven't spoken to him, no.

It's an OS X server, as far as I know. I've tried different OS versions (Tiger, Snow Leopard) and different Firefox versions (well, Zotero doesn't work with very very old versions).

I'm just curious of how the Zotero zip routine works. I don't get why zipping a file from my local disk (USB) works, but zipping a file from the remote server doesn't. If it would be an OS or browser problem, I don't see why this happens only in one of those setups. So, how does Zotero zip the file? Anything I could check there...

I don't know if this uses the built-in ZIP-writing routines, but you could try it:

https://addons.mozilla.org/en-US/firefox/addon/212

Edit #1: Actually, this extension predated ZIP writing in Mozilla, so I suspect it uses its own component.

Edit #2: Yeah, it looks like it uses its own platform-specific code. You could still try it for good measure, but it wouldn't be particularly enlightening if it worked.

Thanks for all your efforts. I'll try this out tomorrow at university. Btw, with "different OS" I meant different OS X versions. There is no Windows at our chair, just Apple everywhere ;-) I know that WebDAV is something completely different, but as you also already said, we eliminated the WebDAV as error reason.