Sequence contains more than one matching element - Bugs & Issues - Bugs & Issues - Progress Community

Sequence contains more than one matching element

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Sequence contains more than one matching element

  • Sequence contains more than one matching element
  • Hi,
    I'm experiencing this issue when I try to open the backend page to manage Pages. I receive this message in a javascript popup windows: "Sequence contains more than one matching element". Could anyone help me to resolve this issue? I cannot manage my website without access to that page.

    Thanks in advance for your support

    Davide Vernole
  • Hello Davide,

    Please check the request and response from the web service that is called when you try to click on pages. Is this a new project, upgraded project or some old installation you are using?

    Kind regards,
    Ivan Dimitrov
    the Telerik team
  • Hii Ivan,
    here your are the request and response that I have captured by using Firebug:

    User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20110303 Firefox/3.6.15
    Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
    Accept-Language: en-us,en;q=0.5
    Accept-Encoding: gzip,deflate
    Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
    Keep-Alive: 115
    Connection: keep-alive
    X-Requested-With: XMLHttpRequest
    Cookie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; .ASPXAUTH=95F3C8C122CB89FD69A2BC427F992C54C602DB9428B487FDC6EBF45A2034F84D67DCF80AC261DDBD0D92B3967CA2D8FEC6141FD4061AB2B2D5A515F4D4F072F3054B3AFBD07FBACFC19B0DF544576BA023645BCAF281074D93FEF125613DFC10088242C926CC4AF36948DB55000A7B2B2E5D24949E21EA0F418C163A5B0EF1681FBFAEC676EBA5A366A6CBCB35CF53AE

    Cache-Control: private
    Content-Length: 61
    Content-Type: application/json
    Server: Microsoft-IIS/7.5
    Set-Cookie: .SFAUTH=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; expires=Mon, 07-Mar-2011 13:47:37 GMT; path=/; HttpOnly
    X-AspNet-Version: 4.0.30319
    X-Powered-By: ASP.NET
    Date: Mon, 07 Mar 2011 11:47:37 GMT


    Response Body:
    "Detail":"Sequence contains more than one matching element"

    Calling the URL by hand I have received this reply:

    File not found
    Firefox can't find the file at ASC.

    This project in an upgrade from Sitefinity 4 to Sitefinity 4 SP1. The .svc file is in the right directory.

  • Hi Ivan,
    I have resolved the issue following an idea that Radoslav has shared with me. Cleaning the sf_draft_pages table from the duplicated draft pages that for any reason could be present in that table. In my support ticket I have suggested to Radoslav a change in your code to avoid this kind of issue again.

    Thanks for your support
  • Same thing happens with me. I tried deleting the records in the sf_draft_page table, but no luck. It seems to happen with really long forms I think.

    Sequence contains more than one matching element

    Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

    Exception Details: System.InvalidOperationException: Sequence contains more than one matching element

    Source Error: 

    An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

    Stack Trace: 

    [InvalidOperationException: Sequence contains more than one matching element]
       System.Linq.Enumerable.SingleOrDefault(IEnumerable`1 source, Func`2 predicate) +467
       Telerik.Sitefinity.Descriptors.DynamicFieldsTypeDescriptor..ctor(ICustomTypeDescriptor parent, Type type) +948
       Telerik.Sitefinity.Model.DynamicFieldsTypeDescriptionProvider.GetTypeDescriptor(Type objectType, Object instance) +354
       System.ComponentModel.DefaultTypeDescriptor.System.ComponentModel.ICustomTypeDescriptor.GetProperties() +63
       System.ComponentModel.TypeDescriptor.GetPropertiesImpl(Object component, Attribute[] attributes, Boolean noCustomTypeDesc, Boolean noAttributes) +412
       Telerik.Sitefinity.Model.DataExtensions.SetValue(IDynamicFieldsContainer dataItem, String fieldName, Object value) +33
       Telerik.Sitefinity.Modules.Forms.Web.UI.FormsControl.SaveFormEntry(FormDescription description) +565
       Telerik.Sitefinity.Modules.Forms.Web.UI.FormsControl.ProcessForm(FormDescription form) +137
       System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +145
       System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3410
  • I'm having this problem on a project as well.   What records need to be cleaned out of the sf_draft_page table?   All of them or only those that are duplicates?

  • Hi Kevin,
    in my case only the duplicate records. This has resolved my issue and now my web site is online.

  • I'm now getting this error.  This is a brand new project under Sitefinity 4.1. 

    Clearing the sf_draft_pages table did not fix the issue.  I can create a new page, but when attempting to edit it, I get the error, "Sequence contains more than one matching element."

    Also, when attempting to edit a single page, I see 2 new records get inserted into sf_draft_pages.  Is this normal?

    I'm running into one issue after the next with Sitefinity...please help!

    -Chris B.
  • Hi Chris Bryant,

    Can you please outline the steps you take in order to reach the problem on the new website? Instead of clearing the page drafts table can you please try using a variation of the code below:
    var manager = PageManager.GetManager();
    var pageDataList = manager.GetPageDataList();
    foreach (PageData pageData in pageDataList)
        var drafts = pageData.Drafts;
        if (drafts.Count > 1)
            for(int i=1;i<=drafts.Count-1;i++)

    All the best,
    Radoslav Georgiev
    the Telerik team

  • Hi,
      I am getting the same error, but mine pops-up as soon as I click on Pages in the backend administration. This started after I attempted moving my dev db to prod. I merged all my dev records with production without deleting anything on the live database. Given the lack of knowledge to know which table means what, or whether we can delete records from certain tables or not, we had to retain the production records. The website seems to be working fine, frontend, however the backend is having issues.

      The lists, templates seem to be okay. Only the Pages is the looming issue. We are going live today and would greatly appreciate any assistance.

  • I had the same problem earlier, it seemed to be linked to a custom control of mine being incorrectly created. It had an error on creation as the Toolboxes.config file was not editable, so it was only partially created. To fix I had a backup of the DB just before, restored it, made sure the config files were writeable and then re-created the controls. You could probably achieve the same by just deleting the config sections in the administrative pages.

    Hope this helps,

  • Thanks for your reply Dan.
    How do I know which config file to clear and what should I clear?  
    Everything is working, only the Pages is having this problem. I cannot go back to my old database cause I need to use the new one to move to production. If it helps I am getting a 500 error when I saw on Fiddler, the url is
    The same is working on Dev. I merged DEV database with production and palced it on Staging whereI am getting this error.

    Any help would be greatly appreciated.

  • Hi Soumya,

    It sounds like to me that your database merge didn't work as expected and that in the process duplicate records have been created in some of the tables. I'm not overly familiar with a lot of the inner workings of Sitefinity so hopefully one of the admins will step in. Sorry I cant be much more help,
  • Hi Dan,

      Thanks a lot for replying back. Regarding the database merge I purposefully did not chose to delete the records on the target DB (production) cause I was not sure which records in which tables could go and which not. This is the price I am ready to pay till I get a better explanation from Sitefinity as to how to handle the merge or hopefully when they have the Site Synchro feature built in.. I will be eagerly waiting :)

      Coming to the error, I cleared the table of duplicates, I went of on is_temp_draft & page id as basis and tried to have only one of each combination.

     Now the errors are gone and everything working fine. I did have some more hiccups cause of the merge, of multiple controls of same id getting created on some pages, but I manually fixed them. I dont like this way, but will have to do till I find a more relaible way.

    thanks again for your response.