Telerik's Image Upload Control not working - getting Unc

I am trying to upload images using the builtin uploader provided by Telerik. I have tried uploading it from Photo Gallery as well the from the actual Content Type's field control but I am getting a "Requested URL was rejected ... ...." error in an alert box from Sitefinity's Html5UploadControl.ashx 

PFA screenshots of error. The uploader is not working on the Live Site, while its working fine on Dev site. I have cleared all the cookies/cache and then tried, I recycled the App Pool & restarted the website but still the issue is not resolved. Please guide.

Regards,

Zepp.

Hi Zepp. Can you please provide error log from App_Data/Sitefinity/Logs

Where are you storing images? DB or FileSystem?

Hello Victor,

    Thanks for replying. The images are being stored in DB. Please find below the error message in the log file : 

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Timestamp: 13/10/37 05:19:27 ص

Message: HandlingInstanceID: 93ef933d-dfb3-4b84-83fe-dcc85d731f0d
An exception of type 'System.Web.HttpException' occurred and was caught.
------------------------------------------------------------------------
07/18/2016 05:19:27
Type : System.Web.HttpException, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Message : Request timed out.
Source : 
Help link : 
WebEventCode : 3001
ErrorCode : -2147467259
Data : System.Collections.ListDictionaryInternal
TargetSite : 
HResult : -2147467259
Stack Trace : The stack trace is unavailable.
Additional Info:

MachineName : XXXXXXX
TimeStamp : 13/10/37 05:19:27 ص
FullName : Telerik.Sitefinity.Utilities, Version=6.3.5000.0, Culture=neutral, PublicKeyToken=b28c218413bdf563
AppDomainName : XXXXXXXXXXXX
ThreadIdentity : 
WindowsIdentity : NT AUTHORITY\NETWORK SERVICE
Requested URL : xxxxxxxx/.../_dwg7190.jpg


Category: ErrorLog

Priority: 0

EventId: 90000

Severity: Error

Title:Enterprise Library Exception Handling

Machine: XXXXXXXX

App Domain: XXXXXXXXX

ProcessId: 6796

Process Name: c:\windows\system32\inetsrv\w3wp.exe

Thread Name: 

Win32 ThreadId:5576

Extended Properties: 
----------------------------------------

Your log from Event viewer. Do you have any sitefinity logs, when error occurs?

Please find below the Log from Event Viewer: 

Event code: 3001 
Event message: The request has been aborted. 
Event time: 12/10/37 04:23:27 ص 
Event time (UTC): 12/10/37 04:23:27 ص 
Event ID: e155582e12cb4bbcabb89637d971adbf 
Event sequence: 2874 
Event occurrence: 5 
Event detail code: 0 
 
Application information: 
    Application domain: XXXXX 
    Trust level: Full 
    Application Virtual Path: / 
    Application Path: x:\xxxx\xxxx\www\xxxx\ 
    Machine name: XXXXX
 
Process information: 
    Process ID: 6520 
    Process name: w3wp.exe 
    Account name: NT AUTHORITY\NETWORK SERVICE 
 
Exception information: 
    Exception type: HttpException 
    Exception message: Request timed out.

Request information: 
    Request URL: xxxxx/.../_dwg7039.jpg 
    Request path: /images/default-source/xxxx/_dwg7039.jpg 
    User host address: xxxxxxx
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: NT AUTHORITY\NETWORK SERVICE 
 
Thread information: 
    Thread ID: 36 
    Thread account name: NT AUTHORITY\NETWORK SERVICE 
    Is impersonating: False 
    Stack trace: 
 Custom event details: 

Turns out there was a restriction from the Network security team of the Application Server which was causing this issue.  Its resolved now. 

Thanks for the support.

Regards,

Zepp.