cms.root.path error after upgrade to 4.7 (Joomla)

Question

I upgraded two installations of CiviCRM 4.6.11 to 4.7 on the same server. Both upgraded fine, but now have the following errors:

1) Systems Settings --> CMS Database integration shows nothing (no paths or fields displayed). Normally I would expect at least a field to enter the Joomla Users Table name.

2) Systems Settings --> Directories shows this error:

<div id="crm-container" class="crm-container" lang="en" xml:lang="en"> <style type="text/css" media="screen"> 
@import url(http://domain.com/administrator/components/com_civicrm/civicrm/css/civicrm.css); 
@import url(http://domain.com/administrator/components/com_civicrm/civicrm/bower_components/font-awesome/css/font-awesome.min.css);
</style> <div class="messages status no-popup"> <i class="crm-i fa-exclamation-triangle crm-i-red"></i> 
<span class="status-fatal">Sorry but we are not able to provide this at the moment.</span> 
<div class="crm-section crm-error-message">Cannot resolve path using "cms.root.path"</div> 
<p><a href="http://domain.com/administrator/" title="Main Menu">Return to home page.</a></p> 
</div> </div> 
<script language="JavaScript"> function toggle( element ) { var parent = element.parentNode; var className = parent.className; if ( className == 'crm-accordion-wrapper collapsed crm-fatal-error-details-block') { parent.className = 'crm-accordion-wrapper crm-fatal-error-details-block'; } else { parent.className = 'crm-accordion-wrapper collapsed crm-fatal-error-details-block'; } } </script>

Anyone else seen anything like this? There are no php errors logged (but some warnings), and the CiviCRM log shows this:

$backTrace = #0 ...civicrm/CRM/Core/Error.php(444): CRM_Core_Error::backtrace("backTrace", TRUE)
#1 ...civicrm/CRM/Core/Invoke.php(57): CRM_Core_Error::handleUnhandledException(Object(RuntimeException))
#2 ...civicrm.php(116): CRM_Core_Invoke::invoke((Array:4))
#3 ...civicrm.php(40): civicrm_invoke()
#4 ...CMS_root_directory.../libraries/cms/component/helper.php(392): require_once("...civicrm...")
#5 ...CMS_root_directory.../libraries/cms/component/helper.php(372): JComponentHelper::executeComponent("...CMS_root_directory.../administrator/components/com_civicrm/civicrm...")
#6 ...CMS_root_directory.../libraries/cms/application/administrator.php(98): JComponentHelper::renderComponent("com_civicrm")
#7 ...CMS_root_directory.../libraries/cms/application/administrator.php(152): JApplicationAdministrator->dispatch()
#8 ...CMS_root_directory.../libraries/cms/application/cms.php(252): JApplicationAdministrator->doExecute()
#9 ...CMS_root_directory.../administrator/index.php(47): JApplicationCms->execute()
#10 {main}

Answer 1

Thanks to eug for finding the problem (see comments). Eug's solution worked for me:

Edit the file administrator/components/com_civicrm/civicrm/templates/CRM/Admin/Form/Setting/Pa‌​th.hlp to replace the first crmResPath with crmResURL

Update: problem persists in 4.7.3. Have upgraded the bug report priority to Major.

Update: problem persists in 4.7.4.

Update: problem persists in 4.7.5.

Update: fix prepared for 4.7.6. See above bug report link for PR details.

Update: problem fixed in 4.7.6.

Answer 2

I updated Civicrm to 4.7.6 in a Joomla 3.5.1 site, with "System Status: Ok" reported as a result. However the reported fix was not there: CMS Database integration shows nothing (no paths or fields displayed) only two buttons.

I manually edited the file as in the answer Jern gave, and then the system reported a sync of users. Still no database-name for the Joomla users is displayed: no path or field. I tested the sync operation and it worked okay, so I guess the field is no longer necessary.

And reset it to the startsituation: my edit was not needed after all, see comment Jern below.