[Zope] upgrade from 2.7.5 to 2.8.6

[Miles Waller]

Hi,

I have just upgraded the staging/test version of a large site from 2.7.5 
to 2.8.6.  When restarting zeo, it seemed to take a 'long' (in the most 
subjective sense) time to come up, and I noticed this entry in the logs:

2006-09-14T17:36:23 WARNING ZODB.FileStorage Failed to load database 
index: exceptions.AttributeError: type object 'BTrees._fsBTree.fsBTree' 
has no attribute '__basicnew__'

Does anyone know what this means?  Is it important/indicative of any 
sort of problem at all that I should be aware of?  Does the storage do 
anything in response to this at all?

When the live version is upgraded, downtime has to be at a minimum, or I 
will get phonecalls ...

Thanks,

Miles