I would guess you have neither Monticello, nor MCInstaller loaded? 
You'll want to install MCInstaller at least to install Monticello packages.

Julian

raymondasselin at sympatico.ca wrote:
> Trying to load Seaside(59) in a fresh Squeak 3.6 (basic) Image I had this error (see the
> attachment).
> Note:  Squeak-3.6g-2 (Unix VM) on MacOSX (Panther) with the following fixes loaded.
> 
> -SMinstallPackage-fix2-dgd.1.cs.gz
> -SMinstallPackage-fix-dgd.1.cs.gz
> -SMDowDirHandleFix-dgd.1.cs.gz
> -MacRootPathNameFix-JMM.1.cs.gz
> 
> Any hints ?
> 
> 
> ------------------------------------------------------------------------
> 
>