Answers.Body: <p>This seems to be similar to: <a href="https://civicrm.stackexchange.com/questions/4793/civievent-error-when-registering-could-not-find-valid-value-for-id">CiviEvent - Error when registering: Could not find valid value for id</a></p>
  
  <p>If you are using WordPress, then setting the base url might help. Copying my response to that issue below:</p>
  
  <p>I was having a similar problem. I noticed the base url for WordPress was not set. </p>
  
  <p>If you haven't set that, try setting that in Administer > CMS Database Integration and let us know if that fixed your issue.</p>
  
  <p>Make sure the event is not the home page, that seems to cause problems with the base url. </p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-09-08T19:25:44.610Z
Answers.LastActivityDate: 2015-09-08T19:25:44.610Z
Answers.LastEditDate: 2017-04-13T12:53:13.167Z
Answers.UserDisplayName: Sanjay Jain
Answers.Body: <p>The most common cause for this is that the form and thanks pages are not being viewed on the same URL; CiviCRM's form handling depends on these not varying, but often (for example) a CiviCRM form displayed on <code>example.org</code> will redirect to <code>www.example.org</code> after submission.</p>
  
  <p>Check that the server base URL is the same before and after your form submission. Check hostname, path, and protocol; the following are example URLs which are NOT the same.</p>
  
  <pre><code>http://example.org
  https://example.org
  http://www.example.org
  https://www.example.org
  http://www2.example.org
  https://www2.example.org
  </code></pre>
  
  <p>If this is affecting your site, the best step to take is to ensure that your webserver is configured to make all URLs <em>canonical</em>.</p>
  
  <p>By ensuring that the form can only be viewed at a single base URL, you can ensure that CiviCRM will not be redirecting a viewer to another base URL after its submission.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-08-27T02:19:19.203Z
Answers.Text: http://civicrm.stackexchange.com/questions/2422/could-not-find-a-valid-session-key-unable-to-save-any-admin-forms and http://civicrm.stackexchange.com/questions/3426/the-dashboard-does-not-render are some other questions relating to canonical URLs and CiviCRM.
Answers.UserDisplayName: Chris Burgess
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-08-27T02:13:29.300Z
Answers.LastActivityDate: 2015-08-27T02:13:29.300Z
Answers.UserDisplayName: Chris Burgess
Body: <p>After our organization updated to the latest version of CiviCRM, our users started receiving the following error after registering for events on our website:</p>
  
  <blockquote>
    <p><strong>Sorry but we are not able to provide this at the moment.</strong></p>
    
    <p>Could not find valid value for id</p>
    
    <p>Return to home page.</p>
  </blockquote>
  
  <p>The user is properly registered on our system and receives a confirmation email.  It seems to be a problem with the thank you screen.  The configuration of the thank you screen is the same as before.</p>
  
  <p>Ideas?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-08-27T02:10:52.863Z
Comments.Text: This is a good question!  To solve your problem, we'll need to see the expanded debugging information.  In CiviCRM, please go to **Administer menu > System Settings > Debugging and Error Handling**, select "Yes" to both "Enable Debugging" and "Display Backtrace", and press "Save".  Repeat the problem that caused your error, and you'll see much a much more detailed error.  Please update this question with the expanded error and backtrace - and don't forget to disable debugging/backtrace when you're done!
Comments.UserDisplayName: Jon G - Megaphone Tech
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-09-08T21:34:45.110Z
Comments.Text: I can confirm that what @Sanjay Jain is saying is true, just tested it right now. So if you are using Wordperss, check that you have properly set the base page navigating to Administer>System Settings>CMS Database Integration.
Comments.UserDisplayName: Andrei
Tags: <civievent>
Title: Why is the event registration "Thank You" page generating an error?
ThreadText: # Why is the event registration "Thank You" page generating an error?
  
  (Asked by: username_0 on 2015-08-27)
  
  After our organization updated to the latest version of CiviCRM, our users started receiving the following error after registering for events on our website:
  
  > **Sorry but we are not able to provide this at the moment.**
  >
  > Could not find valid value for id
  >
  > Return to home page.
  
  The user is properly registered on our system and receives a confirmation email. It seems to be a problem with the thank you screen. The configuration of the thank you screen is the same as before.
  
  Ideas?
  
  **Tags:** civievent
  
  > **Comments:**
  > **username_1**: This is a good question!  To solve your problem, we'll need to see the expanded debugging information.  In CiviCRM, please go to **Administer menu > System Settings > Debugging and Error Handling**, select "Yes" to both "Enable Debugging" and "Display Backtrace", and press "Save".  Repeat the problem that caused your error, and you'll see much a much more detailed error.  Please update this question with the expanded error and backtrace - and don't forget to disable debugging/backtrace when you're done!  
  > **username_2**: I can confirm that what @username_3 is saying is true, just tested it right now. So if you are using Wordperss, check that you have properly set the base page navigating to Administer>System Settings>CMS Database Integration.  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_3 on 2015-09-08. Score: 2
  
  This seems to be similar to: [CiviEvent - Error when registering: Could not find valid value for id](https://civicrm.stackexchange.com/questions/4793/civievent-error-when-registering-could-not-find-valid-value-for-id)
  
  If you are using WordPress, then setting the base url might help. Copying my response to that issue below:
  
  I was having a similar problem. I noticed the base url for WordPress was not set.
  
  If you haven't set that, try setting that in Administer > CMS Database Integration and let us know if that fixed your issue.
  
  Make sure the event is not the home page, that seems to cause problems with the base url.
  
  
  ---
  
  ### Answer by username_4 on 2015-08-27. Score: 1
  
  The most common cause for this is that the form and thanks pages are not being viewed on the same URL; CiviCRM's form handling depends on these not varying, but often (for example) a CiviCRM form displayed on `example.org` will redirect to `www.example.org` after submission.
  
  Check that the server base URL is the same before and after your form submission. Check hostname, path, and protocol; the following are example URLs which are NOT the same.
  
  ```
  http://example.org
  https://example.org
  http://www.example.org
  https://www.example.org
  http://www2.example.org
  https://www2.example.org
  
  ```
  
  If this is affecting your site, the best step to take is to ensure that your webserver is configured to make all URLs *canonical*.
  
  By ensuring that the form can only be viewed at a single base URL, you can ensure that CiviCRM will not be redirecting a viewer to another base URL after its submission.
  
  > **Comments:**
  > **username_4**: http://civicrm.stackexchange.com/questions/2422/could-not-find-a-valid-session-key-unable-to-save-any-admin-forms and http://civicrm.stackexchange.com/questions/3426/the-dashboard-does-not-render are some other questions relating to canonical URLs and CiviCRM.  
  
  ---
  
  