Getting error on submission for private challenges

https://beta-community-app.topcoder.com/challenges/d9b51702-711f-4ee4-93ab-5af4271e83f3/submit user: CustomerUser/appirio123

Same user is able to submit for other challenges. Other users are able to submit to this challenge. This issues is observed with the specific user for this specific challenge. example: Customer user was able to submit to "https://beta-community-app.topcoder.com/challenges/0e19815e-fb7e-4a8c-bb52-6e5c6c101818" without error User "lakshmiathreya" was able to submit to the above challenge without error.

<img width="1440" alt="Screenshot 2020-07-06 at 3 02 49 PM" src="https://user-images.githubusercontent.com/58783823/86578785-fb957900-bf99-11ea-8218-945779d92171.png">

Final Submission Guidelines

Git issue link: https://github.com/topcoder-platform/community-app/issues/4628