Facebook Developer: how to solve the "Page requested not found" error when developing a Facebook application

10 Sep

I’m developing a Facebook application for fun in my free time and found the solution to a problem that nagged me for a while.

To develop a Facebook application, you use the Facebook Developer application and create a new application. You can even define a localhost application so that you can debug your application locally. Once all the required parameters are well defined for you application and you begin to test the Facebook integration, you may encounter the following error when following you Canvas Page URL:

FacebookDeveloper2

When this was happening to me, my application wasn’t being called at all by Facebook. If you have a real error in your application, your application should be called and you should be able to debug it or you should be at least getting a 404 error from your server.

The solutionFacebookDeveloper1

With trial and error, incomprehension and a lot of swearing, I finally found out that this is a bug in Facebook and pinpointed exactly how it happens for me.

Ensure that the Canvas Page URL and that your Side Nav URL are both in lowercase! There is something in the Facebook folks code that forbids you to add any uppercase letters to the Canvas Page URL and Side Nav URL. So, to be on the safe side, for every URL defined in your application’s settings in Facebook, use lowercase letters!

By the way, it now looks like this problem is now specific to the Side Nav URL being in lowercase. I am pretty sure that there was a similar Facebook error when the Canvas Page URL was in uppercase.

20 Responses to “Facebook Developer: how to solve the "Page requested not found" error when developing a Facebook application”

  1. Owen Corpening 07. Oct, 2007 at 2:04 pm #

    Man who would have ever guessed! You Da Man!

    That stumped me everywhich way, maybe 5-8 hours so far … maybe more …

    Reply
  2. viru 19. Oct, 2007 at 7:09 am #

    thanks a lot

    Reply
  3. Askar 28. Dec, 2007 at 12:50 pm #

    All my URLs are in lowercase. It still shows that error…I do have a port number in my URL…does that bother Faceborgs ?

    Reply
  4. Frustrated Developer 27. Jan, 2008 at 12:29 am #

    Thank you! I was getting pretty damn frustrated that this was happening to me and it turns out this bug was the source of the problem.

    Reply
  5. renukadevi 28. May, 2008 at 5:48 am #

    I am using Iframe for Java aplication for intigrating in Facebook , facing problem while redirecting to the application page from Servlet , the page is occupying full Screen with change of Canvas url to call back url instead rendering in the facebook as an application if any body knows the solution plz reply to it

    and how to post mini feeds in profile page if we use Iframe

    Reply
  6. Mike 25. Jun, 2008 at 2:10 pm #

    http://apps.facebook.com/mynextcar/

    My app is this, in setting page, all url is lowercase, but still show this error.

    can you help me?

    holp your help. my account is mike.weib@gmail.com

    Reply
  7. Lenen Hypotheek 15. Nov, 2008 at 8:05 am #

    Man, I’m glad I hadn’t had the same problem. I would have taken me ages to get this solved! :)

    Sometimes things can be so easy :-)

    Reply
  8. andreas 16. Nov, 2008 at 5:11 pm #

    thank you so much for that! was already very frustrated that my facebook development enthusiasm could stop so fast :-)

    Reply
  9. Henning 05. Dec, 2008 at 12:30 pm #

    Wow, thanks for that! I fiddled with that for an hour now.

    I’m really angry about the lost time – how can the developers of facebook be so dumb, and accept an canvas URL that is known not to work…

    I listened around now, and heard only bad things about developing facebook apps…

    Reply
  10. Roger 10. Dec, 2008 at 1:10 pm #

    Thanks a ton — I was going partially insane trying to fix that.

    Reply
  11. Roy 21. Dec, 2008 at 4:13 pm #

    Jerome! We all owe you about 2-3 hours of our lives. Thanks man!

    Reply
  12. Roy Truelove 21. Dec, 2008 at 5:48 pm #

    While we’re on the subject of case sensitivity in Facebook..

    If you :

    Developer Page for your app ->
    DataStoreAdmin ->
    Create Object Type ->
    Type in an object with an uppercase

    The code will silently fail, and just return to the same page. If you change it to lowercase, no problem.

    Reply
  13. Bilal 15. Jan, 2009 at 9:43 am #

    Thanx man, i have wasted many hours of mine in figuring out the problem and then came up with ur post.

    It helped me a lot. :)

    Reply
  14. Pascual 16. Jan, 2009 at 8:45 am #

    Thanks for this post Jerome.

    I just spent half a day trying to figure out why my first app could not get accessed by facebook.

    This should appear in bold in their getting started doc (unless I missed it)

    Reply
  15. Jason Divis 18. Jan, 2009 at 8:47 pm #

    Fabulous! You’d think that the facebook guys would at least put that in their getting started guide: http://developers.facebook.com/get_started.php

    I think I’ll clue them in on this.

    Thanks for the post. I think this just proves, in this day and age, if you’ve followed the documentation, and you’re still having troubles, ask the cloud. Someone else has probably had the same issue and knows the solution.

    You’ve been cataloged in StumbledUpon as well. THANK YOU!

    Cheers!

    -J.

    Reply
  16. PS 18. Jan, 2009 at 8:58 pm #

    There is now a wiki page specifically dedicated to setting up the example footprints application at:

    http://wiki.developers.facebook.com/index.php/Footprints

    Reply
  17. myan 09. Mar, 2009 at 1:07 am #

    wenever i goto http://apps.facebook.com/myapplication i get the following error

    Server Error in ‘/FacebookApp1′ Application.
    ——————————————————————————–

    HTTP Error 404 – Not Found

    Reply
  18. Chirayu 09. Mar, 2009 at 1:18 pm #

    Hey Man!

    great job! i did a lot of swearing too.

    Reply
  19. ankur 05. Apr, 2010 at 5:44 am #

    HOLY SHIT!!! IT WORKS!!!

    FACEBOOK CANT RECOGNISE UPPERCASE CHARACTERS IN FILE !!!!

    Reply
  20. mon 13. Feb, 2011 at 10:50 am #

    I have an error in creating my application.
    I put my canvas url —http://apps.facebook.com/my-application/

    error like
    Error while loading page from myapplication.

    How can I solve this problem?

    Reply

Leave a Reply