I'm in a unique situation - I am a site owner on two separate Sharepoint instances - one is Sharepoint on prem, the other is Online. I am using Nintex 2013 on prem and Nintex for Office 365 for SPO.
In my on prem instance (Nintex 2013), I have a few workflows that query a list for names, dumps them in a collection variable, and sends them an email. No sweat.
The collection variable looks like this:
i:0#.w|farm\shortname1;i:0#.w|farm\shortname2
And emails are sent to this variable value just fine.
In Nintex for Office 365, for some reason, this doesn't work.
Here's what I have. List #1 with a "Subscribers" column (People&Groups), containing names.
List #2 with a list workflow that contains a "Query List" action. The Query List action is querying List #1 for the "Subscribers" column and collecting the values in a collection variable. Under "Columns to Select" I've chosen "Subscribers" and under "With Property" I've chosen "Work email".
The resulting collection variable in Nintex for SPO looks like this:
[{"subscribers":{"EMail":"email1@domain.com"}},{"subscribers":{"EMail":"email2@domain.com"}},{},{},{},{},{}]
The workflow can't send to this, and of course I'm getting this error:
Workflow Status
Looping through collections in Nintex Workflow for Office 365 is different than in Nintex Workflow for SharePoint. The following blog post is a good resource for working with the Query List action in Nintex Workflow for Office 365: