I have been working with Moose 5.0 on a project involving natural language processing. I used TextLint to parse the input, just because it contained a set of parsers which gave output in a convenient form. I have read all about the virtues of Pharo 4, and decided to give it a try, so I set out to reproduce the earlier results. I have run into a number of problems - basically I haven't been able to get anywhere. I realise TextLint is rather antique, but basically as I use it it is just a set of PetitParser parsers, so I can't see a problem. I have boiled the problems down to a few test cases, not realistic bits of my work but just to show the essential points. 1. Environment: Windows 7 Professional (64 bit version). 2. Download and install latest Pharo 4 - Latest update: #40612. This is just to get an up to date VM. 3. Download latest Moose 5.1 image and unzip into same folder as Pharo 4. On opening the Moose 5.1 image it also shows Latest update: #40612. (I have to ignore Firefox's hysterical warnings that the INRIA site does not have a valid security certificate.) 4. Load TextLint into the image. Can't get 'ConfigurationofTextLint' to work, so load TextLInt-Model-JorgeRessia.225.mcz and TextLint-Tests-lr.166.mcz via the Monticello Browser. This is the same as I used in my earlier Moose 5.0 image, where it worked as expected. 5. Open a playground, enter: PPToken on: 'test'. and select 'Inspect it'. The inspector halts with message: 'MNU ByteString>>find AnySubstring:startingAt:' Basic Inspect works as expected. Does this look like the problem raised by Nicolas Lusa today? 6. Enter in the playground: word := (TLTextTokenizer parse: 'test' startingAt: #word) at: 1. (The tokenizer gives an array of tokens, so we need to select the first - and only - one.) Basic Inspect confirms that 'word' is a PPToken, as expected. 7. Enter in the playground: TLWord with: word. Select 'Do it'. The image becomes completely unresponsive, and appears to be in a tight loop. Only way out is to click the Windows red X and say yes to exit without saving. Restarting, get to the same point and select 'Debug it'. Trace it to TLSyntacticElement>>initializeWith: aToken, where the only line of code is: 'token := aToken'. Again a complete lockup. Sorry for the lengthy details; I just hope there is enough there to enable someone to diagnose the problem(s). Any help gratefully received. Meanwhile I am back to the Pharo 3 version. Thanks Peter Kenny