Recently, when migrating a Plone 4 site from one VPS server instance to another, we had the following problem: We were not able to start Zope with Supervisord because it crashed every time we tried to start it. Running Zope in foreground (bin/instance fg) produced the following error: Python: Objects/typeobject.c:1736: extra_ivars: Assertion `t_size >= b_size’…