Hi. It just means that what you are installing does not includes the package that has the control panel.
You are sending class side #load. If you check the method it does "self project stableVersion load".
So you are loading the #stableVersion and the default group. To know what you are exactly loading, you can check in the ConfigurationOfPier2 to see what it includes.
Or you can "simulate" the loading and see what it loads. So if you print:
(Smalltalk at: #ConfigurationOfPier2) project stableVersion ---->>> record. a MetacelloNullRecordingMCSpecLoader(linear load :
linear load : 2.0.9 [ConfigurationOfPier2]
load : ConfigurationOfSeaside30
linear load : 2.0.9 [ConfigurationOfPier2]
load : ConfigurationOfMagritte2
linear load : 2.0.9 [ConfigurationOfPier2]
load : ConfigurationOfMagritte2
linear load : 2.0.9 [ConfigurationOfPier2]
linear load : 3.0.1 [ConfigurationOfSeaside30]
load : ConfigurationOfGrease
linear load : 3.0.1 [ConfigurationOfSeaside30]
linear load : 1.0.1 [ConfigurationOfGrease]
load : Grease-Core-pmm.51
load : Grease-Pharo-Core-pmm.31
load : Seaside-Core-pmm.666
load : Seaside-Pharo-Core-pmm.9
load : Seaside-Canvas-pmm.101
load : Seaside-Pharo-Canvas-lr.3
load : Javascript-Core-lr.88
load : Javascript-Pharo-Core-DaleHenrichs.9
load : Prototype-Core-lr.23
load : Scriptaculous-Core-lr.97
load : JQuery-Core-lr.111
load : JQuery-UI-lr.69
linear load : 2.0.6 [ConfigurationOfMagritte2]
load : ConfigurationOfGrease
linear load : 2.0.6 [ConfigurationOfMagritte2]
load : ConfigurationOfSeaside30
linear load : 2.0.6 [ConfigurationOfMagritte2]
linear load : 3.0.1 [ConfigurationOfSeaside30]
load : Seaside-Component-pmm.85
load : Seaside-HTML5-lr.11
load : Seaside-Session-pmm.134
load : Seaside-RenderLoop-lr.72
load : Seaside-Tools-Core-jf.18
load : Seaside-Flow-jf.22
load : Seaside-Widgets-obi.18
load : Seaside-Environment-pmm.71
load : Seaside-Pharo-Environment-lr.6
load : Seaside-Pharo-Continuation-lr.5
load : Seaside-Pharo-Flow-lr.5
load : Magritte-Model-lr.404
load : Magritte-Morph-lr.53
load : Magritte-Pharo-Model-lr.22
linear load : 2.0.6.1 [ConfigurationOfMagritte2]
linear load : 1.0.7 [ConfigurationOfGrease]
load : Grease-Core-NickAger.70
load : Grease-Pharo-Core-NickAger.49
linear load : 3.0.7 [ConfigurationOfSeaside30]
load : Seaside-Core-NickAger.768
load : Seaside-Pharo-Core-NickAger.16
load : Seaside-Component-jok.92
load : Seaside-Canvas-pmm.117
load : Javascript-Core-lr.90
load : Prototype-Core-lr.25
load : Scriptaculous-Core-pmm.102
load : JQuery-Core-lr.123
load : JQuery-UI-lr.80
load : Seaside-HTML5-pmm.28
load : Seaside-Session-pmm.157
load : Seaside-RenderLoop-lr.73
load : Seaside-Tools-Core-lr.19
load : Seaside-Flow-pmm.23
load : Seaside-Widgets-lr.26
load : Seaside-Environment-NickAger.77
load : Magritte-Seaside-lr.342
load : Magritte-Pharo-Seaside-lr.5
load : Pier-Model-NickAger.421
load : Pier-Pharo-Model-lr.3
load : Pier-Seaside-NickAger.526
load : Pier-Pharo-Seaside-lr.5
load : Pier-Security-NickAger.180
load : Pier-Pharo-Persistency-TudorGirba.20)
As you can see, it doesn't load the package you need. So you can download that manually, or first try to load Seaside alone (with ConfigurationOfSeaside3), making sure to load a group that includes that package, and then you load ConfigurationOfPier2. I think (but I am not sure) that ConfigurationOfPier2 always expected that you load seaside before...if you see in the above list of packages, seaside gets loaded (part of it) just because of dependencies of grease and magritte, but not for Pier itself....
Finally, Notice that it is VERY GOOD (from my point of view) that ConfigurationOfPier2 does not load the panel by default because it depends on OmniBrowser, and the latter is not supported in all platforms.