I downloaded 

  http://tweakproject.org/download/iBuild-3.8-6665.1.zip

filed-in build/install.st to 

  SystemVersion current version 'Squeak3.8'
  SystemVersion current higestUpdate 6665

and got the following error:

  MCHttpRepository(Object)>>doesNotUnderstand: #cachedFileNames
  MCConfiguration>>versionNamed:for:from:
  [] in MCConfiguration>>depsSatisfying:versionDo:displayingProgress: {[:dep |  ver := dep versionInfo name.  repo := repoMap     at: ver     ifAbs...]}
  [] in OrderedCollection(SequenceableCollection)>>do:displayingProgress: {[:each :i |  bar value: i.  aBlock value: each]}
  OrderedCollection(SequenceableCollection)>>withIndexDo:
  [] in OrderedCollection(SequenceableCollection)>>do:displayingProgress: {[:bar | self   withIndexDo: [:each :i |     bar value: i.    aBlock value: e...]}
  [] in ProgressInitiationException>>defaultMorphicAction {[result := workBlock value: progress]}
  BlockContext>>ensure:
  ProgressInitiationException>>defaultMorphicAction
  ProgressInitiationException>>defaultAction
  UndefinedObject>>handleSignal:
  MethodContext(ContextPart)>>handleSignal:
  MethodContext(ContextPart)>>handleSignal:
  ProgressInitiationException(Exception)>>signal
  ProgressInitiationException>>display:at:from:to:during:
  ProgressInitiationException class>>display:at:from:to:during:
  ByteString(String)>>displayProgressAt:from:to:during:
  OrderedCollection(SequenceableCollection)>>do:displayingProgress:
  MCConfiguration>>depsSatisfying:versionDo:displayingProgress:
  MCConfiguration>>upgrade

How do I recover from this?