Use of SpotlightSearchTool() returns "Model Catalog error: Error Domain=com.apple.UnifiedAssetFramework Code=5000" , although model is available

On macOS Golden Gate Developer Beta 4 the following code:

import CoreSpotlight
import FoundationModels
  
let tool = SpotlightSearchTool()

let session = LanguageModelSession(tools: [tool])

let response = try await session.respond(to: "What hikes have I gone on?")

, returns the following error:

Model Catalog error: Error Domain=com.apple.UnifiedAssetFramework Code=5000 "There are no underlying assets (neither atomic instance nor asset roots) for consistency token for asset set com.apple.modelcatalog" UserInfo={NSLocalizedFailureReason=There are no underlying assets (neither atomic instance nor asset roots) for consistency token for asset set com.apple.modelcatalog}

, although the model is available in general and can return responses without using the tool. The code:

print(SystemLanguageModel.default.availability) 

returns 'available'.

What am I doing wrong?