Issues with TWAIN acquisition on IE

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igor
Posts: 17
Joined: Fri Oct 28, 2016 10:42 pm

Issues with TWAIN acquisition on IE

Post by igor » Tue Dec 20, 2016 2:08 pm

Hello,

I am building a document scanner in our ASP.NET client application. During testing I noticed an acquisition problems in IE11 browser.

First problem was related to communication between DocuVieware control and TWAIN Connector service. After JavaScript debugging, I found out that jQuery ajax post inside the ajax.PostBaseRequest function fails with error message "No transport". This issue prevented me to run acquisition process.
I have made a workaround for this issue by adding following line inside jQuery document ready function:

Code: Select all

$.support.cors = true;
Second problem apeared during acquisition. Inside browser's console I found statement:
'atob' is undefined
docuvieware-min.js (289,216)
After quick googling, it turned out that atob function is not supported by IE.

Could you advice me how to deal with above issues? We need support IE in our software. Currently we are using DocuVieware 12.0.44.

While testing, I was using following browsers:
  • Internet Explorer 11
  • Edge 20
  • Chrome 55
  • FireFox 50
  • Opera 42
Above issues occur only in IE.
Regards,
Igor Paszewski
FileHold Systems Inc.

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Loïc
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Re: Issues with TWAIN acquisition on IE

Post by Loïc » Tue Dec 20, 2016 5:31 pm

Hello Igor,

Thank you for the report.

Could you try with our latest 2.0.49 version? The problem should be solved.

You can directly try the twain acquisition demo online through this page: http://www.docuvieware-demo.com/twain_demo.aspx

Please let me know if you need further assistance.

With best regards,

Loïc

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igor
Posts: 17
Joined: Fri Oct 28, 2016 10:42 pm

Re: Issues with TWAIN acquisition on IE

Post by igor » Mon Feb 13, 2017 9:46 am

I've updated my SDK to version 12.0.58. Issues that I described in my previous post do not appear any more. Unfortunately, I still have some troubles with TWAIN on Internet Explorer and Edge browsers.

In general, when I open the acquisition dialog, I get information that TWAIN connector is not installed or running. Of course, I've installed it before and I'm sure it is working fine since on other browsers like Chrome or FireFox my application behaves correctly. I did a JS debugging and it turned out that function GetTwainAcquisitionServiceInfo call fails with AJAX error:
Error: Access is denied
In further investigation I run your demo application that you mentioned in your last post but it also fails.

I was testing on Windows 8.1 (Enterprise) and Windows 10 (Enterprise). Both machines were after fresh system installation and have default settings of Internet Options, firewall etc. This issue surprised me because on my local computer everything is working properly on all browsers.

Is there anything you could improve in the communication between viewer control and the TWAIN connector? Or maybe, do you have any instructions how to configure securements on the computer in order to make working the TWAIN acquisition?
Regards,
Igor Paszewski
FileHold Systems Inc.

Cedric
Posts: 259
Joined: Sun Sep 02, 2012 7:30 pm

Re: Issues with TWAIN acquisition on IE

Post by Cedric » Wed Feb 15, 2017 6:01 pm

It could be caused by the default security settings in those operating systems versions (I'm not familiar with Entreprise edition and it appears to work on every machine I tried on so at this point this is only a theory but that's the only reason I can think of).
With Microsoft browsers with default security settings, an "Access is Denied" error can be raised when attempting to access a resource in the "Local intranet" zone from an origin in the "Internet" zone (or the other way around).
I think you can work around this error by adding the origin site to the "Trusted sites" security zone, in case of TWAIN acquisition, adding something like http://localhost:56856/* (not sure about the * or if the / is required though) could do the trick.

I can't really put this theory to the test because I am not able to replicate the described failure. I will try to build a test setup with 8.1 and 10 in their Entreprise version and see if I can reproduce.

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igor
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Re: Issues with TWAIN acquisition on IE

Post by igor » Wed Mar 08, 2017 12:53 pm

Thank you for the previous reply.

I would like to clarify one more thing related to the TWAIN acquisition since I didn't anywhere find this information. Does the TWAIN acquisition work when I configure my ASP.NET application to run over HTTPS protocol? During my tests it turns out that acquisition does not work. When are you planning to support TWAIN over HTTPS? I'm currently using version 12.0.58 of your SDK.
Regards,
Igor Paszewski
FileHold Systems Inc.

Cedric
Posts: 259
Joined: Sun Sep 02, 2012 7:30 pm

Re: Issues with TWAIN acquisition on IE

Post by Cedric » Wed Mar 08, 2017 12:56 pm

Only HTTP protocol is supported in DocuVieware 2 but we have been working on this and the next major release that will be published later this month will support HTTPS.

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igor
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Re: Issues with TWAIN acquisition on IE

Post by igor » Wed Mar 08, 2017 12:59 pm

Thank you for the quick reply.
Regards,
Igor Paszewski
FileHold Systems Inc.

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igor
Posts: 17
Joined: Fri Oct 28, 2016 10:42 pm

Re: Issues with TWAIN acquisition on IE

Post by igor » Tue Mar 14, 2017 6:23 pm

I would like to return to my previous issue with "Access is denied" on Edge. Your suggestions about adding http://localhost to the Intranet zone didn't work for me. However I found out that it is related to the localhost loopback. I learned that Edge treats localhost as Internet site (not Intranet), so features like integrated authentication do not work. I've added the Edge to the LoopbackExempt list and it worked like a charm. Below is a full command:

Code: Select all

CheckNetIsolation LoopbackExempt -a -n="Microsoft.MicrosoftEdge_8wekyb3d8bbwe"
Edge has an option in about:flags under "Developer settings" called "Allow localhost loopback". Unfortunately checking this option does not work. I found information that Windows has bug in this area. There is a link to the reported issue: https://developer.microsoft.com/en-us/m ... /10082889/

Could you refer to above workaround? Were you able to setup test environment and try to reproduce my issue?

My current OS version is: Windows 10 Enterprise 1607 (build 14393.693). Edge: 38.14393.0.0.
Regards,
Igor Paszewski
FileHold Systems Inc.

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