Encountering error when launching Fiddler Classic right after installing it.

[Evan]

Here's the error message it told me to paste onto here. I have tried uninstalling and reinstalling Fiddler but nothing changed.

 

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Loading custom MIME mappings failed
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Fiddler has encountered an unexpected problem. If you believe this is a bug in Fiddler, please copy this message by hitting CTRL+C, and submit a bug report at http://www.telerik.com/forums/fiddler.

The cloud file provider is not running.



Type: System.IO.IOException
Source: mscorlib
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)

   at System.IO.FileStream.ReadCore(Byte[] buffer, Int32 offset, Int32 count)

   at System.IO.FileStream.Read(Byte[] array, Int32 offset, Int32 count)

   at System.Xml.XmlTextReaderImpl.InitStreamInput(Uri baseUri, String baseUriStr, Stream stream, Byte[] bytes, Int32 byteCount, Encoding encoding)

   at System.Xml.XmlTextReaderImpl..ctor(String url, Stream input, XmlNameTable nt)

   at System.Xml.XmlTextReader..ctor(Stream input)

   at System.Xml.Serialization.XmlSerializer.Deserialize(Stream stream)

   at Fiddler.XmlFileMimeMappings..ctor(String filePath)

   at Fiddler.frmViewer.PrepareConsumer(Object info, EventArgs counter)


Fiddler v5.0.20251.1171 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 10.0.22631.0] 
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OK   
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[Nick Iliev]

Hello Evan,

 

The most likely reason for the issue is that Fiddler can't access the Documents folder which is probably in OneDrive. The issue is explained in detail in the following thread:

https://www.telerik.com/forums/got-a-error-when-first-starting-fiddler#5150730 

You can try starting Fiddler Classic as administrator (so that the app has privileges to access the cloud folder).

 

Regards,
Nick Iliev
Progress Telerik