Custom fields that are from an external plugin do not correctly load on Orion

Custom fields that are from an external plugin do not correctly load on Orion

We can see this on the support site when we restart Support. The custom fields disappear. If you refresh the cache, then all is well again. This also interfeared with the correct upgrading process.

This may be caused by the custom field cache being populated during the instantiation of CustomFieldManager before the external plugins have been loaded.