Damaged and/or incomplete files...

[Cr00zng]

The MacBook Pro laptop has OSX El Capitano, version 10.11.6; the latest updates had been applied two days ego. Since then...

The standard account logged in to apply the latest updates, by entering root account credentials, stopped working. Logging in with this UID is not an issue, albeit somewhat slower than other accounts. The issue is that none of the applications are actually working. For example, when trying to open App Store, this is the error that pops up:



All other applications have the the exact same error, well, other than the application name changes. The finder shows no applications:



Opening the "Utilities" folder shows this:



The "Launchpad" only shows the calender with actual icons, all others have a blank page with the letter "A" right corner

The are two other accounts on this Mac, a standard user and the root account. These accounts can login just fine and run any of the apps, including system apps.

Deleting/recreating the account in question is an option, but...

What's the cause for this issue and how to fix it? There will be times when deleting the account might not be an option.
TIA...

 

[Slydude]

I did some poking around and one suggestion for this is to open the Security & Privacy preference pane and set it to allow software from anywhere. I personally don't like that solution but it might be worth a try.

Are you experiencing other weird behaviors?

 

[ferrarr]

Can you start up in Recovery to run First Aid on the start up disk? Have you reset NVRAM?

 

[Cr00zng]

@Sly...

I had not experienced any other issues, weird, or otherwise in other accounts. The system runs as it should within the same performance levels it had been. The exception is a single account that probably has the profile damaged. I've found at the Apple site the very same issue described and possible resolution:

Q: El Capitan: You can't open the application 'app name' because it may be damaged or incomplete

I've looked in to the referenced folder and this is what mine shows:

Machine-name:/ UID$ cd var
Machine-name:var UID$ cd folders
Machine-name:folders UID$ ls
55	92	9j	d2	zz
Machine-name:folders UID$

The folder "55" is the new user ID I've just created today, in preparation to removing the account with issues. Based on the date the folders had been created, I can match the UID to folder names. For example, the folder named "d2" contains the troubled UID temporary and cache files. This folder could be deleted, with root access, and the system would generate a new folder for this UID. Effectively restoring access to apps. At least that's what the link seems to suggest.

@ferrarr...

Thanks for the links, but I am not at the point to do that. Three out of four UIDs work just fine and at this point, I don't believe that it would fix the account with the issues.

 

[Slydude]

Nice find and I think you are right about what this suggests unless I am misunderstanding something. Might be worth giving that a try.

I wondered earlier if it wasn't a corrupt Finder preference or two but this seems more likely. If you try this let us know whether or not it works.

I'm still wondering how I missed that when I searched earlier. The Google foo must be strong in you.

 

[Cr00zng]

@Sly...

Thanks for your help...

That was no Google foo, I don't use Google. I used DuckDuckGo, seems better for technical searches.

I crossed my finger and with your suggestion, ran this command:

Machine-name:folders UID$ sudo rm -iR d2

"i" for confirming deletion, didn't want to blow away the whole system by accident. After entering the password, it took awhile, lot of "y" and "Enter", the command deleted everything. Logged back in with the account in question and voila, everything works as it should including the performance is back. While user data had been backed up, deleting the temporary and cache files did not delete user data. In retrospect, duh, but it does not hurt to back up files...

Based on my research and what I've seen on my system, the subfolder named "zz" is the template for users' temporary and cache files. Corrupted folders can be deleted as described above and new ones will be created when the user logs on the first time.

Sweet.... if I am right...

 

[Slydude]

@Sly...

Thanks for your help...

That was no Google foo, I don't use Google. I used DuckDuckGo, seems better for technical searches.

Nice work. I use DuckDuckGo as well for basically everything. I like the fact that ads basically aren't there and I don't think it does the level of tracking that Google does.
Is there such a thing as DuckDuckGo foo?

 

[Cr00zng]

As far as you and I concerned, yes, there is DuckDuckGo foo... ;D

Is there a way to mark this thread resolved? I am sure there's but it hides from me...

 

[Slydude]

As far as you and I concerned, yes, there is DuckDuckGo foo... ;D

Is there a way to mark this thread resolved? I am sure there's but it hides from me...

There isn't but no real need to do so. Around here we tend to leave threads open unless they degenerate into something that violates forum rules.

 

[Cr00zng]

There isn't but no real need to do so. Around here we tend to leave threads open unless they degenerate into something that violates forum rules.

In that case, um... ;D

I just could not stop looking for purpose of the "/var/folders/". The best I could come up with is at this link:

http://www.magnusviri.com/OS_X_Admin/what-is-var-folders.html

The relatively short version...

The "/var/folders/xx" folder, actually just the the "xx" part, is created when the user logs in the first time. Each users have their own system assigned folder, with sub-folders of temporary and cache folders. On my system, this is how they look for a standard UID:

Machine_name:~ UID$ getconf DARWIN_USER_TEMP_DIR
/var/folders/d2/j5gmfyg157z_7gfplhlym8_m0000gq/T/

Machine_name:~ UID $ getconf DARWIN_USER_CACHE_DIR
/var/folders/d2/j5gmfyg157z_7gfplhlym8_m0000gq/C/

Yes, the “5gmfyg157z_7gfplhlym8_m0000gq” sub-directory name is generated by the system, based on the UUID and other factors. The intent is probably to hide the users’ temporary directories from malware.

Items in the temporary directory deleted by the system after three days, if they have not been used. The cache directory is not deleted by the system and presumably keeps growing. It’s possible that the cache folder is intended for performance improvement, similarly to prefetch on Windows, by copying the content in to memory at startup. The content of both folders are deleted if and when the system is booted in safe mode.

The user assigned folder, “d2”, and its subfolders can be deleted by the root account, without much of an issue to the UID in question, just don’t delete the folder named “folders”. The “getconfig” command can be used to match the two characters folder name to the UID as shown above. The standard user ID could not delete its own folder.

The folder “/var/folders/zz/” is special in a sense that it is not assigned to any named user. The root account has its own two character folder that also can be safely deleted. I did not find any reference that the “zz” folder can be safely removed, or not, nor would I want to test it on my system.

Now we know how these folders created and what we can do with them, let’s muddy up things a bit…

The “/var/folders/” structure is a symlink to the “/private/var/folders”. Deleting the user assigned folder, “d2” in my case in either directory structure, will delete the “.../var/folders/d2/” and all its content in both folder structures. At the first time the user logs in, these directory structure is recreated by the system at both locations.

I did say relatively short...