Error when configuring link between Jira issue and slack channel

[Kristine Donate]

I have the Slack Integration app enable for our instance of Jira cloud and I am attempting to connect a specific Jira issue with a specific Slack channel.  Somehow this worked once, but never again. 

I select the Slack tab while the specific Jira issue is open in the browser and click on the Create button.  In the form, I choose my Slack channel from the drop down and enter in a channel description.  Then under events, I select the triggers for which notifications should occur.  After clicking the create button I get an error similar to the following.  Any ideas?

Also, assuming this is supposed to work, I noticed private channels are not present in the channel selection drop down.  How am I supposed to link a Jira issue to a private Slack channel?

Error from attempt to link Jira issues with Slack channel:

ErrorException in 31e945f54a8fd9b36b827c4697d69eed70581202.php line 27:Invalid argument supplied for foreach() (View: /app/resources/views/issue/message-row.blade.php) (View: /app/resources/views/issue/message-row.blade.php) (View: /app/resources/views/issue/message-row.blade.php)