I can't migrate from 3.3 into 4.3.12. Due to following error:
Traceback (most recent call last):
File "/plone/buildout-cache/eggs/Products.CMFPlone-4.3.12-py2.7.egg/Products/CMFPlone/MigrationTool.py", line 259, in upgrade
step['step'].doStep(setup)
File "/plone/buildout-cache/eggs/Products.GenericSetup-1.8.6-py2.7.egg/Products/GenericSetup/upgrade.py", line 166, in doStep
self.handler(tool)
File "/plone/buildout-cache/eggs/plone.app.upgrade-2.0.0-py2.7.egg/plone/app/upgrade/v40/betas.py", line 151, in convertToBlobs
output = migrateATBlobFiles(context)
File "/plone/buildout-cache/eggs/plone.app.blob-1.5.17-py2.7.egg/plone/app/blob/migrations.py", line 161, in migrateATBlobFiles
return migrate(self, walker=getATBlobFilesMigrationWalker)
File "/plone/buildout-cache/eggs/plone.app.blob-1.5.17-py2.7.egg/plone/app/blob/migrations.py", line 35, in migrate
walker = walker(context)
File "/plone/buildout-cache/eggs/plone.app.blob-1.5.17-py2.7.egg/plone/app/blob/migrations.py", line 157, in getATBlobFilesMigrationWalker
return getMigrationWalker(self, migrator=ATFileToBlobFileMigrator)
File "/plone/buildout-cache/eggs/plone.app.blob-1.5.17-py2.7.egg/plone/app/blob/migrations.py", line 24, in getMigrationWalker
return CustomQueryWalker(portal, migrator, use_savepoint=True)
NameError: global name 'CustomQueryWalker' is not defined