To reproduce:

1. Allow guest access to course.
2. Login as user not enrolled in course and access it as a guest.
3. Attempt to view activities.

The following error message is displayed when attempting to view an assignment:

Sorry, but you do not currently have permissions to do that (View assignment)

Stack trace:

• line 943 of /lib/accesslib.php: required_capability_exception thrown
• line 66 of /mod/assignment/type/uploadsingle/assignment.class.php: call to require_capability()
• line 51 of /mod/assignment/view.php: call to assignment_uploadsingle->view()

The following error message is displayed when attempting to view a chat:

Sorry, but you do not currently have permissions to do that ({$a})

Stack trace:

• line 379 of /lib/setuplib.php: moodle_exception thrown
• line 2060 of /calendar/lib.php: call to print_error()
• line 736 of /mod/chat/lib.php: call to calendar_event->update()
• line 36 of /mod/chat/view.php: call to chat_update_chat_times()

The following error message is displayed when attempting to view a forum:

You do not have the permission to view discussions in this forum

The following error message is displayed when attempting to view a database activity:

Sorry, but you do not currently have permissions to do that (View entries)

Stack trace:

• line 943 of /lib/accesslib.php: required_capability_exception thrown
• line 88 of /mod/data/view.php: call to require_capability()

The following error message is displayed when attempting to view a wiki:

Create page permission needed

Stack trace:

• line 943 of /lib/accesslib.php: required_capability_exception thrown
• line 934 of /mod/wiki/pagelib.php: call to require_capability()
• line 100 of /mod/wiki/create.php: call to page_wiki_create->print_content()