Hi Ann-Marie,

Product Manager for Perform here, I've had a chat with the technical team around this issue and I'll see if I can summarise what I've learned;

It sounds like you've created two separate performance activities, where the briefing summary will redisplay some responses from the application form. 

The expected flow is that the application form will be completed first, and then the briefing summary will pull in elements of the application form once completed. 

I believe you may run into your error if the briefing summary instances are created either at the same time as, or too soon after the application form instance is completed. This is because there would not have been enough time for a cron run in-between the two activities, so the briefing summary would be referencing something that doesn't yet exist at its time of creation. 

One way you might prevent this error from occurring would be to have the briefing summary instances created a few days later than the application form activity instances; even better if you are able to use the closure of the application form activity as a reference point. 

I hope this helps and if I find out anything else I'll let you know!

Ashley