Map tiles are jumbled up, corrupting map

6 posts, 1 answers
  1. Daniel
    Daniel avatar
    2 posts
    Member since:
    Aug 2016

    Posted 27 Sep 2016 Link to this post

    The attached files show what I see when I run the SDK Samples Browser and choose the OSM or Bing provider examples. Basically the map tiles appear in the wrong places and so you get a mixed-up "jigsaw puzzle" effect. This doesn't happen at the initial zoomed-out level, but happens immediately when I change the zoom. It also happens as I scroll around.

    However, I only see this when running inside our corporate network! I don't see the problem when running the same SDK sample on my home network. The same is true for several of my colleagues.

    Our IT manager says this problem must be due to a bug in Telerik. He also reports that he sees the problem on his home network and he produced a similar screenshot.

    How can I go about troubleshooting this issue? What could be causing the map tiles to get mixed up?

  2. Answer
    Martin
    Admin
    Martin avatar
    1164 posts

    Posted 28 Sep 2016 Link to this post

    Hello Daniel,

    Once in a while a scrambled tiles issue pops up. Nevertheless, we can't reproduce it on our side. But it seems that, mostly, this could happen when a proxy server is used or there are internet (or other network) connection issues. You can double check if your work systems are making their data transfer with the world wide via a proxy. And also your can see your internet performance.

    Also, you can try different tile caching options for the map. By default RadMap uses the built-in .NET caching mechanism and the default request cache level is set to CacheIfAvailable. You can try different levels using the map provider's RequestCacheLevel property and set the IsTileCachingEnabled property to False. Another thing you can try is to manually delete the tiles cache.
    string profile = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
    string cachePath = profile + "\\TelerikMapCache";
    Directory.Delete(cachePath, true);

    Any additional information about your device/network setup could be useful for investigating this.

    Regards,
    Martin
    Telerik by Progress
    Do you need help with upgrading your AJAX, WPF or WinForms project? Check the Telerik API Analyzer and share your thoughts.
  3. Daniel
    Daniel avatar
    2 posts
    Member since:
    Aug 2016

    Posted 04 Oct 2016 in reply to Martin Link to this post

    Hi, turns out we are using Sophos proxy in our internal network and your OSM example demonstrates it is broken! :)

    We can create or stop the problem by changing proxy settings in the Internet Options dialog in Control Panel (also clearing the browser cache between tests, as the broken/good data remains in the cache which can cause further confusion when troubleshooting).

    Thanks for your help. We are now looking for business approval to buy Telerik licenses.

  4. Noble
    Noble avatar
    1 posts
    Member since:
    Jan 2017

    Posted 05 Jan in reply to Daniel Link to this post

    Hello Martin,

    You had mentioned in this post that you were able to workaround the issue "by changing proxy settings".

    Do you remember what settings you had changed?

  5. Peter
    Peter avatar
    16 posts
    Member since:
    Oct 2016

    Posted 12 Jan in reply to Noble Link to this post

    Hi Martin,

    I work alongside Daniel. As far as I am aware we got a temporary fix for this by requesting our network admin to configure the proxy so that requests to OSM and Bing map servers are allowed straight through. It appears that without this the Sophos proxy caches tiles, and it seemed like the cache behaviour was incorrect. We've raised this with Sophos but have not had any more permanent resolution of the issue. 

    Pete.
  6. Tim
    Tim avatar
    4 posts
    Member since:
    May 2013

    Posted 4 hours ago Link to this post

    I am seeing this exact behaviour (wrong map tiles loading/map tiles jumbled up) for Bing & OSM providers on my work network. I have checked with our IT dept and we are not using any kind of proxy for out internet connection. When I first tried the RadMap control several months ago it all worked perfectly, loading all tiles as expected.

    Is there anything else I can try to resolve this?

    I have tried both of the options below on a very simple view in a WPF desktop application but still get tiles loading as in the attached image. I have tried setting IsTileCachingEnabled = false and all options for RequestCacheLevel. Also tried manually deleting the cache. None of this had any noticeable effect.

    <telerik:RadMap HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
        <telerik:RadMap.Provider>
            <telerik:BingRestMapProvider ApplicationId="<BINGMAPSAPPLICATIONID>" />
        </telerik:RadMap.Provider>
    </telerik:RadMap>
     
    <telerik:RadMap HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
        <telerik:RadMap.Provider>
            <telerik:OpenStreetMapProvider/>
        </telerik:RadMap.Provider>
    </telerik:RadMap>

     

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