Hi,
From the description it seems that it is a problem of permissions.
Basically if you set the permissions on the role properly (end user permissions), it gives the permissions to run the whole role unit, with all the content within the role. so you just need to verify that you gave permissions to the applications the content is using (security zones).
In case the error is really "access denied" in the trace, then you can just follow the following troubleshooting guide to solve the issue:
Troubleshooting the "Access Denied" Message in the Portal
In this blog check section D, which is relevant for your case.
In addition there are references to the HowTo guides (according to version) to make sure that you set the permissions properly in the portal.
Thanks & regards,
Michal