This happened the other night when I d/l'ed and ran the Safari WebKit Nightly Build, and it's also happened once or twice before (under circumstances that I can't recall specifically, but that dealt with Safari installations)...

When I installed the Nightly Build, something caused my AdBlock For Safari database in /Users/Your short name/Library/Safari/LocalStorage to become corrupt.

If you, like I, have spent considerable time and effort configuring your AdBlock database so Websites you regularly visit render in a fashion that pleases to you I most emphatically recommend that you keep a current backup of /Users/Your short name/Library/Safari/LocalStorage against, so to speak, the fall of night.

The first time I encountered this issue it took me hours to recreate the browsing experience I had created for myself and lost.

I filed a bug report with Apple many months ago, but nothing seems to have come of it. Additionally, AdBlock's developer has disclaimed knowledge/responsibility.

I take it you don't use Time Machine?

Nor did I even remember that it exists when I posted.

On the other hand, though, wouldn't it be easier to maintain a backup in the same folder as the original than to go the Time Machine route to recover from a "disaster?"

And, of course, there are any number of Mac users besides me who don't use Time Machine.

If you make it a practice to manually back up that folder, I suppose that that's easy, but Time Machine makes it effortless. I have, once or twice, used TM to revert to a previous version of a file and it's quite painless. I also maintain a SuperDuper clone but TM is worth the trouble to set up. After that, you don't have to do anything except let it run.

I'm going to respond to your post by retroactively restating my response to dk to anticipate it...

My intention was not to discuss backup strategies; it was to point out that there may be an innocuous, well-hidden file on your Mac in which you, without particularly realizing it, have invested a large amount of time and effort and that is subject to some unpredictable corruptive force, and that even if your backup strategy is "I don't need a backup strategy," that one file may be your mind-changer.

This also affected me with other extensions and I didn't really make much headway with my bug report. However once you upgrade and recreate preferences, they work from that point forward.

I had problems with the following extensions: User CSS, Ninjakit & Better Facebook where it was causing the same LocalStorage corruption.

You can read up on my conclusions here:
Webkit Bug Report

> This also affected me with other extensions and I didn't really make much headway with my bug report. However once you upgrade and recreate preferences, they work from that point forward.

I, too, filed a bug report, but I was pretty much at a loss when it came to describing precisely what the bug was or how to reproduce it.

The problem is recreating those prefs (AdBlock's, anyhow); I've got an enormous amount of time invested in mine, and the one time I had to recreate them (before I learned to back up) was a real hair-puller.

In this case backups only help with reverting, but not with moving forward because even the backups would corrupt once they're used by the new version.

I ended up copy / pasting any text that I could from my extension settings into a text file and then took screen shots of any settings screens to re-create them all.

I don't use AdBlock so I don't know how complicated it settings are for re-creating in that manner.

Frankly I don't use AdBlock and other extensions like it because I haven't found one yet that doesn't decrease the loading performance of the browser.

My issue with AdBlock appears to have been different than what you've experienced; replacing its corrupted database with my backup has invariably resolved my issue with no down-the-road consequences. (Edit:The issue did recur when I was experimenting with WebKit, but only when I got into four process mode and killed two of them; I guess it was the bouncing that caused it.)

AdBlock's settings can be easily recreated using your methodology, but are a real nuisance to recreate from scratch if you use it as I do... Early on, I discovered that AdBlock is a misnomer...that it should be called ElementBlock, because it can block any element of an html page, up to and including the entire page.

Accordingly, I've used AB to block any and all eye-candy on all the Websites I visit regularly, sometimes effortlessly , sometimes with much trouble, the FTM logo at the top of the Forums List page (effortlessly), by way of example.

And if I take a slight loading hit as a result of using AB, it's both unnoticeable to me and preferable to seeing the extraneous garbage (No! Not the FTM logo.) with which many Websites greet me.