Task module Crash on detail view: 7.13.0 -> 7.13.3

I discovered a problem with the CRM update.

After looking through the code under /data
I can see that the system is capable of either figuring out the metadata dynamically (I think this is needed for the aggregate subpanels) or via a file.

There are a bunch of metadata files that define the relationships for the aggregate subpanels (like activities)

These files are within the custom/metadata folder.

Look for files named tasks_activities_1_<FIELDNAME>MetaData.php
These need to be removed as they cause chaos when the relationships are being constructed.