Categories visible, data not: Corrupted database?

For the Zotero database I'm using for an important project, on which I've done a lot of work, I've suddenly found my categories intact but my data no longer visible.

My backup files, unfortunately, have the same problem.

I am using Zotero version 1.0.0rc3, Firefox version, running under Windows Vista Business.

The problem doesn't seem to be due to a Zotero upgrade. I have been using this version of Zotero successfully with this database for some time.

When my laptop is running on batteries I've had problems with Windows sometimes freezing and therefore needing to be ungracefully rebooted. I've speculated that the database may have been corrupted during such a shutdown and reboot.

I sent my database to the Zotero Database Repair Tool. But the database I received back as a replacement doesn't seem to solve the problem.

I looked at the "report errors" dialogue, and it seemed to report nothing significant. And now the menu item for it is greyed out.

What shall I do?

Thank you.

O Govinda

PS: I am now in the United Arab Emirates, but on the 25th I will be leaving the UAE for a village in India where my internet connection will be of poorer quality. I'd be exceedingly grateful to have this Zotero project up and running again before then.
  • Well, you might try upgrading to 1.0.0rc5 from the home page to see if that fixes the problem.

    If not, if you still remember the Upload ID from the repair tool (or want to generate another one), you can send it to and we can take a look.

    Does your database pass the integrity check in the Advanced Section of the Zotero prefs? If so, and Report Errors isn't becoming active, I'm not really sure what else I'd be able to suggest without looking at the SQLite file.
  • Thank you very much for the quick response, Dan.

    * Upgrading to 1.0.0rc5 didn't help.

    * The database passes the integrity check.

    I've sent the Upload ID to "support@. . ."

    Standing by. . . .
  • Dan wrote me by e-mail:

    >Your database actually looks fine to me... You may have an extension
    >conflict--try disabling all extensions except Zotero and see if that
    >fixes the problem, and if so, then try re-enabling them one by one.

    And that did indeed solve the problem.

    The demon was. . . the Megaupload Toolbar extension, version (Found at Which I didn't need anyway.

    As soon as I uninstalled it, all was well.

    A million thanks, Dan. And another million on top of that!

    Yours with extreme relief and gratitude,
    O Govinda
  • I looked into this further. It actually seems Megaupload used Zotero as a template for some of their core code, but that's entirely—if bizarrely—coincidental.

    In case anyone's interested in the technical details, Megaupload includes a library that extends the core JS object (extends Object.prototype, in JS-speak), which is generally considered to be not very neighborly at all. There are ways to code around it, but they clutter up otherwise clean code, and it'd be much easier for other extension authors not to do this in the first place.

    (Extending Array.prototype is another matter, and we have an open ticket to fix any remaining places where we don't properly protect against extended arrays. (Due to Zotero's architecture, we only have to do this in some of the code base.) In the name of defensive coding, we may add protections against Object.prototype modifications in the future, but for the moment it's safer to just break completely.)
This discussion has been closed.