#561 7-Zip Fails to Properly Unzip File via Context Menu and CMD, But Works in GUI

[John Kondo]

Hello, I sent some messages a few days ago in another thread that got some response, I still haven't find a way to fix my issue, so I thought it was a better idea to open a ticket to be able to find a solution to this.
Here are the previous messages and the answer provided :

Me :

Hello,

I'm currently encountering a problem with a .zip archive made using 7zip. Whenever I try to unzip it using the context menu (right click -> 7zip -> extract here) or using a bat script (or cmd) "C:\Program Files\7-Zip\7z.exe" e -y archive.zip -bb3 -slt I don't have any logs explaining(*) what is wrong with the process. My RAM is way far from being on full usage, it just uses 10gigs out of 32, I also have enough place on my machine storage.

BUT whenever I'm opening the 7zip GUI and navigate to my archive and then extract it from here, it works.

My archive is created through 7zip so I cannot use builtins Expand-Archive because it doesn't work through the context menu or the powershell as well. (It says the archive is empty)

My zip archive is not damaged because this exact same zip can be unzipped using cmd on another machine using the same version of 7zip.

Details :

7zip versions tested : 24.06, 24.04 and 19.0 (first version used to write this script)

(*) Logs from CMD :

Cannot open the file as [zip] archive
The file is open as [7z] archive

--
Path = D:...\myArchive.zip
Open WARNING: Cannot open the file as [zip] archive
Type = 7z
Physical Size = 713624835
Headers Size = 297
Method = LZMA2:20
Solid = +
Blocks = 3

• archive.sql
• another.sql
  58% 1
  When used in a longer bat script, it doesn't make the script stop. It just act as if the unzip went well and that it could be treated.

Thanks

Igor Pavlov

It's not zip archive.
It's 7z archive.
And 7-zip shows warning that filename extension is not correct.

Me

Thanks for your answer,

Changing extension name to .7z didn't change behavior on this specific machine. We tried to extract it on another machine and it worked properly.

In our script creating the archive, we use the -mx3 option to create the 7z archive faster. We noticed that when creating the archive without this option, it is working normally. Thing is that we wanted to keep using the -mx3 option because it saves us 20 minutes

Nevermind, concerning the -mx3 option, we tried again without it and it's not working anymore.

Igor Pavlol

So do you have any error messages or another issues after changing archive extension to .7z?

Me

No, no more logs than what i sent earlier. Is there a way to find any more logs than -bb3 and -slt ?

If you have any idea about what else can be tested we would be glad to know.

Thanks a lot.

[Igor Pavlov]

descibe it simpler.
describe only one problem in message.
include also command that you use to create archive.

[John Kondo]

Hello,

When I try to unzip a 7zip archive created with the following command :

"C:\Program Files\7-Zip\7z.exe" a -mx3 -t7z -sdel archive.7zip toArchive\*

It stops in the middle without any errors.

It only works when i'm using 7zip GUI. But it's not working through the context menu or through the cmd :
"C:\Program Files\7-Zip\7z.exe" e -y archive.zip -bb3 -slt

it doesn't even output any errors.

Details :

7zip versions tested : 24.06, 24.04 and 19.0 (first version used to write this script)
RAM : 32gb (~22free when unzipping)
I also have enough storage on my machine.

What is really weird is that this same archive can be unzipped on another machines.

[Igor Pavlov]

When I try to unzip a 7zip archive

what command do you use to unzip?

It stops in the middle without any errors.

why do you think that it stops?
why do you think that it stops in the middle?

"C:\Program Files\7-Zip\7z.exe" a -mx3 -t7z -sdel archive.7zip toArchive\*

that command is not good, because 7z archive must have .7z filename extension:

"C:\Program Files\7-Zip\7z.exe" a -mx3 -t7z -sdel archive.7z toArchive\*

[John Kondo]

Yes sorry I mistyped it was supposed to be

"C:\Program Files\7-Zip\7z.exe" a -mx3 -t7z -sdel archive.7z toArchive\*

"C:\Program Files\7-Zip\7z.exe" e -y archive.7z -bb3 -slt

why do you think that it stops?

The console output is the following :

archive.sql
another.sql
58% 1

and then it stops.

Currently we are using this to make it work, but its not optimal.

"C:\Program Files\7-Zip\7z.exe" a -mx3 -tzip -sdel archive.zip toArchive\*

[Igor Pavlov]

maybe the problem with number of cpu threads (if it's 7-zip bug), or it's hardware failure.
What Windows version and hardware specification (CPU/RAM)?
Try these commands:

7z t archive.7z -bb
7z t archive.7z -bb -mmt1
7z t archive.7z -bb -mmt2

[John Kondo]

Thank you for pointing out that, I tried running with those commands, and using 1 or 2 threads solved the problem. It's definitely a hardware problem. Have a great day

[Igor Pavlov]

Now we can't be sure that it's hardware problem.
And if it's bug in 7-zip, I want to fix that bug.
Please do more tests.
check RAM with memtest programs.
try 7-zip benchmark. It also check the RAM.

7z t archive.7z -bb -mmt2
7z t archive.7z -bb -mmt3
7z t archive.7z -bb -mmt4
7z t archive.7z -bb -mmt5
...

and try to find exact conditions where it doesn't work.
Does it stop at same point, if you run test command again?