Updates: Cc: stephane.ducasse Comment #3 on issue 3595 by Torsten....@astares.de: problem starting up with a script on windows http://code.google.com/p/pharo/issues/detail?id=3595 If you debug both you will notice that ProjectLauncher>>startUpAfterLogin has changed. First there is a check if the given argument (the script name/location) has a protocol like http, file or ftp. If not then the url is "manually" adjusted to file-protocol in Pharo 1.1 isUrl ifFalse:[scriptName := 'file:',scriptName]]. So I get 'file:c:\Foo.st' in Pharo 1.1. here and my Script works. In Pharo 1.2 this is replaced by some URI magic that allows for relative paths: "Allow for ../dir/scriptName arguments" scriptName := (FileDirectory default uri resolveRelativeURI: scriptName) asString]]] In my example that just returns 'c:\Foo.st' (since it is now relative) which results in not loading the stuff if you give an absolute path. Note that there is also a comment: "Allow for ../dir/scriptName arguments" I think this was DONE TO NOW SUPPORT RELATIVE PATHS TOO - maybe for Coral scripting system. If you want to give an absolute path you have to use the file protocol since otherwise it is interpreted as a relative path. That is the effect of the change So C:\pharo\core\1.2\Pharo.exe C:\pharo\core\1.2\PharoCore-1.2.image file:c:\Foo.st works without a problem. Since relative paths are now supported too you can also write: C:\pharo\core\1.2\Pharo.exe C:\pharo\core\1.2\PharoCore-1.2.image ../../../../c:\Foo.st So I think this is not a bug, mainly a "not yet documented new feature".