Now it even works

sources/AcediaEnvironment.uc

@@ -51,7 +51,7 @@ var private LoggerAPI.Definition errNotRegistered;
 protected function Constructor()
 {
     //  Always register our core package
-    RegisterPackage_S("AcediaCore.Manifest");
+    RegisterPackage_S("AcediaCore");
 }
 
 /**
@@ -73,7 +73,7 @@ public final function bool RegisterPackage(BaseText packageName)
     }
     _.logger.Auto(infoRegisteringPackage).Arg(packageName.Copy());
     manifestClass = class<_manifest>(DynamicLoadObject(
-        packageName $ manifestSuffix, class'Class', true));
+        packageName.ToString() $ manifestSuffix, class'Class', true));
     if (manifestClass == none)
     {
         _.logger.Auto(errNotRegistered).Arg(packageName.Copy());