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259599-ug: Update more information about IIS OCR ( net 8.0) troubleshooting details #1740

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Nov 7, 2025
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259599-ug: Update more information about IIS OCR ( net 8.0) troubleshooting details #1740

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259599-ug: Update more information about IIS OCR ( net 8.0) troublesh…
sameerkhan001 Nov 6, 2025
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Merge branch 'hotfix/hotfix-v31.2.2' into 259599-ug
chinnumuniyappan Nov 6, 2025
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Merge branch 'hotfix/hotfix-v31.2.2' into 259599-ug
SF4119Subhasri Nov 6, 2025
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Merge branch 'hotfix/hotfix-v31.2.2' into 259599-ug
SF4119Subhasri Nov 6, 2025
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Merge branch 'hotfix/hotfix-v31.2.2' into 259599-ug
SF4119Subhasri Nov 7, 2025
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33 changes: 33 additions & 0 deletions Document-Processing/PDF/PDF-Library/NET/Working-with-OCR/Troubleshooting.md
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Expand Up @@ -491,6 +491,39 @@ NuGet: <a href="https://www.nuget.org/packages/SkiaSharp.NativeAssets.Linux.NoD
</tr>
</table>

## IIS Fails to Load Tesseract OCR DLLs
<table>
<th style="font-size:14px" width="100px">Exception</th>
<th style="font-size:14px">The application failed to load Tesseract OCR DLLs when hosted on IIS, resulting in the error:
Could not find a part of the path 'C:\inetpub\wwwroot\VizarCore\x64'.</th>
<tr>
<th style="font-size:14px" width="100px">Reason
</th>
<td> * IIS couldn't load the required Tesseract and Leptonica DLLs because some system components were missing.<br>
* The Visual C++ Redistributables for VS2015-VS2022 (x86 and x64) were not installed.<br>
* IIS on a 64-bit server needs both redistributables to load native libraries correctly.<br>
* The application's folder paths and permissions were not properly set up for OCR binaries.<br>
</td>
</tr>
<tr>
<th style="font-size:14px" width="100px">Solution</th>
<td>
<b>Installed Required Redistributables</b><br>
Installed both <b>VC_redist.x86</b> and <b>VC_redist.x64</b> for VS2015-VS2022 on the IIS server.<br>
<b>Updated Server</b><br>
Applied all available Windows updates (including cumulative and Defender updates) to ensure system stability.<br>
<b>Configured Application Paths</b><br>
Set default paths for OCR binaries:<br>
* C:\inetpub\wwwroot\myapp\Tesseractbinaries<br>
* C:\inetpub\wwwroot\myapp\tessdata<br>
<b>Set Proper Permissions</b><br>
Ensured IIS_IUSRS group has <b>Read & Execute</b> and <b>List folder contents</b> permissions on the above directories.<br>
<b>Observed Delayed Activation</b><br>
OCR functionality did not activate immediately-likely due to IIS caching or delayed DLL loading-but began working shortly after configuration.<br>
</td>
</tr>
</table>

## OCR not working on Azure App Service Linux Docker Container: Exception has been thrown by the target of an invocation
<table>
<th style="font-size:14px" width="100px">Exception</th>
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