Corrupted Preferences Files - How?

[Bill Hunt]

I apologize that this is concerning Photoshop (CS2 in my case), but might hold true for PSE, as well.

Trash your Prefs! You know the mantra. When PS fails to do something, it’s “trash your prefs!”

I wondered why/how one’s preferences ever get corrupted. I’ve use PS, since 2.5 on all sorts of PC’s, sometimes with it running around the clock for days. Never once had I encountered a corrupted preferences file — until now, that is.

What I encountered can only be listed as an “observation.” I’m sure that it is but one possible cause. Still, I thought that I’d share my experience.

Up at 4:00AM to start a rush scan job. Everything boots up fine, and I start PS CS2. As it’s loading the plug-ins, etc., I notice that Sun Microsystems’ Java wants an update and its icon has appeared in the Tasktray of my XP-Pro SP3. I open it, and click “Update Later,” or whatever the exact dialog is. It drops back to the Tasktray. PS seems to be taking a long time to load on my workstation, but I give it a few moments. Nothing. It’s hung at “Reading Text Global Resources.” I check Task Manager — PS is shown as “Not Responding.” Odd, this has NEVER happened before in all those years. Not so much as once.

I remembered that there was an update for Extend Script, that I told PS to hold off on. I go to Updates, via Bridge and it’s still there waiting. I End Task for PS and look for something usable from MS. Of course there’s nothing. Event Viewer shows an “Application Hang,” with no useful info. I install the Extend Script Update, and try PS again. It gets to the same spot and hangs.

OK, I allow Java to update (making sure to NOT allow the installation of the MSN Search Toolbar - sheezh! I try PS yet again. Hang at the same spot.

Re-boot and hang. Though I have said it a thousand times, “trash your prefs,” it takes a moment for it to sink in. I trash my prefs and all is good with PS. Luckily, I had my dual-monitor Workspace saved, and it only takes a minute to change the default preferences back to what I want.

Normally, I have everything, and I mean everything, set to NOT auto-update. I turn this “feature” off for every program that I install. I use Premiere a lot, and do not want Norton, or anybody, waking up and phoning home. I’ll tell ‘em when to update. Well, I missed Java.

I can only guess that it did it’s update thing, just at a critical time for PS’s loading and blew up the prefs file. Had it popped up a second later, or maybe a second earlier, I doubt that I’d have had to trash my prefs. After all these years (decades really), I had a corrupt preferences file.

I’m sure there are a myriad things that can corrupt a preferences file, and I am only guessing at what caused mine. However, the timing is perfect, so Java gets the blame.

Just thought I’d share,

Hunt

[Steve Grisetti]

Good observations, Hunt!

[Bob]

Guilt by association. It probably was just a coincidence.

The preference file can be corrupted by an incomplete write to disc such as when you terminate a hung task from the task manager or the system has a power interruption. Corruption can also occur because the internal data in Photoshop gets messed up for some unexplained reason and bad data gets written to the file. Photoshop itself is multithreaded, it's possible that two internal tasks tried to update the file at the same time and overwrite each other -- that's rare with well written programs, but I've seen it happen. Rarely, the physical media is flakey and you have a bad or marginal sector. It can't be corrupted by another program randomly accessing a disc sector and making changes. For a non-kernal application to change a file, it has to specifically open that file by name. That's unlikely.

[Bill Hunt]

Bob,

I can easily see how an image file (or a Premiere Prproj/Prel) could easily be corrupted with all sorts of interruptions during read/write phases. Since the preferences file is only updated, when one makes changes to it, and is just read during startup, I kinda' doubt that most things would ruin it. Obviously, I could be very wrong in this. I also do not see how the Java updater could mess with it either, especially as I had yet to click on anything related to it. It was just a pop-up, at the time.

Going back sometime ago, I was in the process of installing Pinnacle S-10.5.1 update, when my Logitec wireless mouse Set-Point driver decided that it would update right in the middle of the install, even though it's auto updating was turned OFF. Well, it not only killed my install, but basically killed my entire system. System Restore would not function. A repair installation of XP would not function. No Ghost backups, including the slip-stream BU disks would work. A new installation of Ghost would not work. All networking was killed and the machine ran like a 286 with DOS 2 on it. It took a complete low-level format of the boot disk and complete re-install of everything to get it running again. I have never had such a catastrophic failure in all of my years with computers. That too seemed improbable, but I was at the helm, when it happened.

I liked the use of the term, "guilt by association." Yes, it could be a coincidence, but PS ran perfectly the evening before, and everything shut down perfectly. There were no changes to the preference file. Heck, I had not changed anything, since I re-built the system after the Pinnacle/Set-Point fiasco, about 3 years ago.

Like I said, it was just an observation, though the second time that something trying to update, when another app was starting, or installing hit at an inopportune moment. At least now I know what it's like to have the prefs get hosed, as happens to so many others. Since the re-writing of the prefs, PS has launched perfectly four times today, and has run perfectly with Painter, AfterEffects, Encore and Premiere Pro 2 all up and going at the same time. In the meantime, I did put handcuffs on Java!

Thanks for the thoughts,

Hunt

[Bob]

Since the preferences file is only updated, when one makes changes to it, and is just read during startup, I kinda' doubt that most things would ruin it.

Bill,

Actually the preferences file contains a lot of dynamic data that Photoshop tracks for use from one session to another and that is written to the file immediately whenever the data changes. Lots of chances for something to go wrong.

The Pinnacle/mouse driver disaster was unfortunate, but it's more likely a result of two installations running at the same time both updating the registry and changing dll files or drivers at a system level. That can really scramble things up good. The preferences file is essentially a private application data file, not a system file, and it's difficult to imagine how that would be affected by the Java update. Still, possibly something at the os level may have delayed writes to the preferences file and things got out of sync. Not supposed to happen, but who knows.

Anyway, I'm with you. I set all my preference to not do automatic updates and install them when I'm ready to install them. I'm not a happy camper when that's ignored and an update tries to run on its own.!

[Bill Hunt]

Bob,

Thanks for the input. After I read your first reply, my thought was to go and look at the prefs file more closely, date, etc. Unfortunately, I have a house full of guests, so I'll have to revisit that plan. However, you have given me much to think about and I'll get back with findings, plus will probably learn something about files that I have takne for granted for decades!

Hunt