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I am using the sample VB.NET that is found in the downloads on http://www.icsharpcode.net/OpenSource/SharpZipLib/Download.aspx.

 When I create a zip file with the CreateZipFile project and then attempted to open it with the Windows XP Compress Folders untility, first I see a blank file listing in the contents window; then when I use the Extract wizard I get an dialog box "Windows has blocked access to these files to help project your computer."  I follow the instructions to unblock the zip file but the "Unblock" checkbox is not there.

I am using the NET 2.0 binary files found on the same web page above.

All of the VB project files upgraded ok to NET 2.0 and work with each other.  I tried different Compression Methods in the sample code but had the same problem.

I have another utility to examine the zip file and it appears as if some extraneous stuff is showing up at the end.

Any ideas?

 Dennis

 

 

 

Hi,

Its not clear whats going on as unblocking a blocked file has always worked.  Are you using Vista?

Are there multiple NT streams for the generated files?  A special stream is used to mark files as blocked.

Cheers, -jr-

I ran into the same issue as you.. The XP Compress Folder utility would open up blank and would give me the "Blocked access" msg when try to Extract all.. I noticed that Win Zip and 7 zip had no problems opening it, but the files were deeply burried in the folder structure of the source files..

 

I then changed the code to not specify file path and just name.. That did the trick.. I think windows is trying to validate that path and when it can't it freaks out..

 Not sure exactly if thats true but the work around did the trick..

 A combination of two things perhaps?

A blocked file that also contains absolute/invalid paths that XP doesnt like?

-jr-

 

I have exactly the same issue. Windows can’t unpack zip files created with latest library (8.85.4).  XP shows error like “Windows has blocked access to these files”  and Vista just “Invalid zip file”. WinRar and 7Zip can unpack these files with no problem. It is real issue for me because I must support in my application standard windows way to handle zip files. Also I can say previous version of CSharpZipLib which I used before (something from year 2006) didn’t have such issue.

I found what issue is. Latest library uses zip64 format by default and standard XP zip utility can’t unpack it. I was wrong about Vista it can unpack with no problem. I solve my issue to switch to use old zip format by setting UseZip64.Off. It works now.

hi...

I want to try your method but I don't know how/where to set the UseZip64 to off.  I am not a coder, is this a non-code editing method I can try?  Please help me fix this issue.

thank you.

jj

 

 

 

 On the Zipfile you are creating, set UseZip64

e.g.

Zipfile zf = new Zipfile();

zf.UseZip64 = UseZip64.Off;

Thanks for the quick reply.  However, I am not creating a zipfile.  I am trying to open a zip file in an Outlook attachment but was unable to open the file with the Windows built-in zip utility because Windows had blocked these type of files.  I am not a coder, is there a way to open this zip file using the Windows build-in zip utility and not a third-party program such as Winzip? 

thanks again.

 

jj

 

 I believe it most likely Outlook that is blocking the attachment not Windows per se.

Google for Outlook blocking attachment

there are plenty of pages on that

Hi DavidP..

thanks for the suggestion, i did searched and followed some instructions to unblocked attachments within Outlook but still doesn't work.  can anyone provide a non-coding method to resolve this issue?  or provide a complete list of codes and instructions on how to run the code for people that are not a coder/developer?

thanks for your time and help.

jayj

 

 

 

Hi Apokrif...

i posted couple question on how resolve this issue or how to edit and run the code.  please see below.  thanks for your help.

------------

Thanks for the quick reply.  However, I am not creating a zipfile.  I am trying to open a zip file in an Outlook attachment but was unable to open the file with the Windows built-in zip utility because Windows had blocked these type of files.  I am not a coder, is there a way to open this zip file using the Windows build-in zip utility and not a third-party program such as Winzip? 

thanks again.

---------------

thanks for the suggestion, i did searched and followed some instructions to unblocked attachments within Outlook but still doesn't work.  can anyone provide a non-coding method to resolve this issue?  or provide a complete list of codes and instructions on how to run the code for people that are not a coder/developer?thanks for your time and help.jayj

 

 

 

 Not sure if we understand your issue so this is how I see it.

•  you receive a zip file as an attachment in an email
• you are using Outlook - what version?
• you do not know what utility created the zip file
• you get an error about windows blocking access to the file - can we see the exact error and context

Please let me know if above is wrong.

Have you tried saving the zip file to disk and double clicking it, instead of running it directly from Outlook. Maybe your firm has policies bccoking execution of files frojm the temp directory. 

If you are not a coder and trying to use SharpZip to get around a technical or company policy I think you would be better to post in a Windows help forum. You need to write and compilea  program to be able to use Sharpzip.

DP... answer below.

 

•  you receive a zip file as an attachment in an email  - Yes. OS: XP
• you are using Outlook - what version? - Outtlook 2007
• you do not know what utility created the zip file - No.  I want the zip file be open by the default XP integrated zip utility instead of Winzip.
• you get an error about windows blocking access to the file - can we see the exact error and context - I double-click on the zip attachment in Outlook and the file opened a blank page instead unzip the content.  So I copied the file to the Desktop and opened it there.  When I double-clicked the zipfile from the desktop, the message "Windows has Blocked Access to these Files" pop-up. 

          I had followed and tried all the suggestions from this forum - such as disabling and enabling zip association, unblocking zip file opening option in Outlook, etc.  However, still doesn't work.  Please help...

thank you.

jay.j

 

A quick google retrieved the following advice:

 To open a blocked file, follow these steps:

1. Right-click the blocked file, and then click Properties.
2. In the General tab, click Unblock.