I was playing around with Conpherence rooms a bit, created a room, added some messages, left the room and entered the room again. However, every time when I re-enter the room now I am greeted with the following error message:
> **Unhandled Exception ("InvalidArgumentException")**
> Argument 1 passed to array_select_keys() must be of the type array, null given, called in /path/to/phabricator/src/applications/conpherence/query/ConpherenceThreadQuery.php on line 404 and defined
Also my avatar is not added to the member list on the right-hand side and the last message in the chat window is:
> ti removed a participant: ti.
This here is hopefully the full stack trace from the PHP error log:
```
[11-Jun-2015 17:01:02 America/Los_Angeles] [2015-06-11 17:01:02] ERROR 2: Invalid argument supplied for foreach() at [/path/to/phabricator/src/applications/conpherence/query/ConpherenceThreadQuery.php:371]
[11-Jun-2015 17:01:02 America/Los_Angeles] arcanist(head=master, ref.master=7d15b85a1bc0), phabricator(head=master, ref.master=bdef1255e398), phutil(head=master, ref.master=92882eb9404d)
[11-Jun-2015 17:01:02 America/Los_Angeles] #0 ConpherenceThreadQuery::loadWidgetData(array) called at [<phabricator>/src/applications/conpherence/query/ConpherenceThreadQuery.php:135]
[11-Jun-2015 17:01:02 America/Los_Angeles] #1 ConpherenceThreadQuery::loadPage() called at [<phabricator>/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php:228]
[11-Jun-2015 17:01:02 America/Los_Angeles] #2 PhabricatorPolicyAwareQuery::execute() called at [<phabricator>/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php:168]
[11-Jun-2015 17:01:02 America/Los_Angeles] #3 PhabricatorPolicyAwareQuery::executeOne() called at [<phabricator>/src/applications/conpherence/controller/ConpherenceWidgetController.php:32]
[11-Jun-2015 17:01:02 America/Los_Angeles] #4 ConpherenceWidgetController::handleRequest(AphrontRequest) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:226]
[11-Jun-2015 17:01:02 America/Los_Angeles] #5 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:140]
[11-Jun-2015 17:01:02 America/Los_Angeles] #6 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phabricator>/webroot/index.php:21]
[11-Jun-2015 17:01:02 America/Los_Angeles] [2015-06-11 17:01:02] EXCEPTION: (InvalidArgumentException) Argument 1 passed to array_select_keys() must be of the type array, null given, called in /path/to/phabricator/src/applications/conpherence/query/ConpherenceThreadQuery.php on line 404 and defined at [<phutil>/src/error/PhutilErrorHandler.php:200]
[11-Jun-2015 17:01:02 America/Los_Angeles] arcanist(head=master, ref.master=7d15b85a1bc0), phabricator(head=master, ref.master=bdef1255e398), phutil(head=master, ref.master=92882eb9404d)
[11-Jun-2015 17:01:02 America/Los_Angeles] #0 <#2> PhutilErrorHandler::handleError(integer, string, string, integer, array) called at [<phutil>/src/utils/utils.php:505]
[11-Jun-2015 17:01:02 America/Los_Angeles] #1 <#2> array_select_keys(NULL, array) called at [<phabricator>/src/applications/conpherence/query/ConpherenceThreadQuery.php:404]
[11-Jun-2015 17:01:02 America/Los_Angeles] #2 <#2> ConpherenceThreadQuery::loadWidgetData(array) called at [<phabricator>/src/applications/conpherence/query/ConpherenceThreadQuery.php:135]
[11-Jun-2015 17:01:02 America/Los_Angeles] #3 <#2> ConpherenceThreadQuery::loadPage() called at [<phabricator>/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php:228]
[11-Jun-2015 17:01:02 America/Los_Angeles] #4 <#2> PhabricatorPolicyAwareQuery::execute() called at [<phabricator>/src/infrastructure/query/policy/PhabricatorPolicyAwareQuery.php:168]
[11-Jun-2015 17:01:02 America/Los_Angeles] #5 <#2> PhabricatorPolicyAwareQuery::executeOne() called at [<phabricator>/src/applications/conpherence/controller/ConpherenceWidgetController.php:32]
[11-Jun-2015 17:01:02 America/Los_Angeles] #6 <#2> ConpherenceWidgetController::handleRequest(AphrontRequest) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:226]
[11-Jun-2015 17:01:02 America/Los_Angeles] #7 phlog(InvalidArgumentException) called at [<phabricator>/src/aphront/configuration/AphrontDefaultApplicationConfiguration.php:229]
[11-Jun-2015 17:01:02 America/Los_Angeles] #8 AphrontDefaultApplicationConfiguration::handleException(InvalidArgumentException) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:230]
[11-Jun-2015 17:01:02 America/Los_Angeles] #9 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:140]
[11-Jun-2015 17:01:02 America/Los_Angeles] #10 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phabricator>/webroot/index.php:21]
```
Let me know if you need more information.