Symptoms

When opening the "Work" mode in a Rapid Board, the following error appears on the top of the screen:

Exception: Uncaught TypeError: Cannot read property 'text' of undefined

Diagnosis

Upgrading to JIRA 6.1.x from JIRA Agile 6.0.8 or lower. 

Cause and possible solutions:

This can be caused by more than one thing:

• The Board's estimation:

  If you go to the board's configuration and click on the Estimation tab, the "Estimation Statistic" is probably set to use the Original Time Estimate and the "Time Tracking" to use the Remaining Estimate and Time Spent. If so, go to Administration > Issues > Field Configuration and check if the field configuration in use by this project don't have the Time Tracking hidden for any Issue Type.
  Basically, the board is trying to check the Remaining Estimate and the Time Spent from all issues there, but can't find it for the one specific Issue Type, like subtasks. A workaround for that could be set the Time Tracking there to "None", so it will consider only the estimations and not look for the time tracking itself in the issues. Or show the Time Tracking field for all Issue Types instead in the Field Configuration.

  This bug is being tracked here.

• A broken Index:

  For some reason, the indexes of JIRA Agile can be broken. A simple re-index would be enough if that's the problem.
  
  

• A third-party plugin:

  Some installed plugin could be causing problems in the JIRA Agile functionalities.
  
  1. Browse through Administration > Plugins > Manage Add-Ons and then click on "Enable safe mode" (this will disable all plugins);
  2. Enable only JIRA Agile;
  3. Check if the problem persists;