In a latest trunk image, fully updated, I tried to 'load from disk’ my older preferences. It fails because in DiskProxy>comeFullyUpOnReload: the code does 

	globalObj := Smalltalk at: symbol ifAbsent: [
		preSelector == nil & (constructorSelector = #yourself) ifTrue: [
			Transcript cr; show: symbol, ' is undeclared.'.
			(Undeclared includesKey: symbol) ifTrue: [^ Undeclared at: symbol].
			Undeclared at: symbol put: nil.
			^ nil].
		^ self error: 'Global "', symbol, '" not found'].
The symbol is #Context

Saving a new preferences file and reloading seems to work. I’ve no idea where the #Context comes from and pretty much any attempt to look through the stack starts firing off annoying notifiers because the ‘aDataStream’ parameter in the IdentityDictionary>readDataFrom:size: is nil by this point.
Is this crucially important? Probably not but it will annoy anyone with a preferences file.

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Science is imagination equipped with grappling hooks.