Replication steps:-

1. Delpoy attached pack
2. Attempt the two question as student, donot click "finish".
3. Click "exist activity" instead
4. Go back and restart your attempt to see the error.
   Copying my comment from the linked issue:-
5. I dug a little deeper. The problem happens when you attempt the package, exit the activity after finishing both question but donot click "finish". And than restart the attempt.
6. There is no error when you finish attempt in the middle of the pack and restart it later.
7. The error is basically since $result->sco is returned as an array containing a sco object where as the code expects it do be the sco object itself.
8. Dump of $result without error case:-

   stdClass Object

   (

   [toc] => <div id="scorm_layout">

   <div id="scorm_toc">

   <div id="scorm_tree">

   <ul>

   <li>

   <a title="a=7&scoid=23&currentorg=ORG-D0F45010CE879ED4C2A2CFD700E3F8F4&attempt=1"><img src="http://ankit.moodle.local/int/master/moodle/theme/image.php/standard/scorm/1353901637/incomplete" alt="Incomplete" title="Incomplete" />&nbsp;Start Quiz&nbsp;</a> </li>

   </ul>

   </div></div></div>

   <div id="scorm_navpanel"></div>

   [toctitle] => Flash Custom (Single SCO)

   [sco] => stdClass Object

   (

   [id] => 23

   [scorm] => 7

   [manifest] => MANIFEST-3A3A393295D01FA6530767F976AF706A

   [organization] => ORG-D0F45010CE879ED4C2A2CFD700E3F8F4

   [parent] => ORG-D0F45010CE879ED4C2A2CFD700E3F8F4

   [identifier] => ITEM-0B4EA308CA525F05ACA9283381611BD9

   [launch] => test.html

   [scormtype] => sco

   [title] => Start Quiz

   [isvisible] => true

   [parameters] =>

   [maxtimeallowed] => 0000:30:00:00

   [timelimitaction] => continue,no message

   [masteryscore] => 80

   )

   [prerequisites] => 1

   [incomplete] => 1

   [attemptleft] => 1

   )

9. Dump of $result during the error:-

   stdClass Object

   (

   [toc] => <div id="scorm_layout">

   <div id="scorm_toc">

   <div id="scorm_tree">

   <ul>

   <li>

   <a title="a=6&scoid=21&currentorg=ORG-D0F45010CE879ED4C2A2CFD700E3F8F4&attempt=2"><img src="http://ankit.moodle.local/int/master/moodle/theme/image.php/standard/scorm/1353901637/failed" alt="Failed" title="Failed" />&nbsp;Start Quiz&nbsp;(Score:&nbsp;50)</a> </li>

   </ul>

   </div></div></div>

   <div id="scorm_navpanel"></div>

   [toctitle] => Flash Custom (Single SCO)

   [sco] => Array

   (

   [0] => stdClass Object

   (

   [id] => 21

   [scorm] => 6

   [manifest] => MANIFEST-3A3A393295D01FA6530767F976AF706A

   [organization] => ORG-D0F45010CE879ED4C2A2CFD700E3F8F4

   [parent] => ORG-D0F45010CE879ED4C2A2CFD700E3F8F4

   [identifier] => ITEM-0B4EA308CA525F05ACA9283381611BD9

   [launch] => test.html

   [scormtype] => sco

   [title] => Start Quiz

   [isvisible] => 1

   [parameters] =>

   [maxtimeallowed] => 0000:30:00:00

   [timelimitaction] => continue,no message

   [masteryscore] => 80

   [prereq] => 1

   [statusicon] => <img src="http://ankit.moodle.local/int/master/moodle/theme/image.php/standard/scorm/1353901637/failed" alt="Failed" title="Failed" />

   [url] => a=6&scoid=21&currentorg=ORG-D0F45010CE879ED4C2A2CFD700E3F8F4&attempt=2

   [incomplete] =>

   )

   )

   [prerequisites] => 1

   [incomplete] =>

   [attemptleft] => 1

   )

10. As pointed out earlier this doesnt seem to have to do anything with the issue in hand, this is a whole different context.

Thanks