When upgrading from 9.1 to 10.1, some virtual services were throwing the error "asset not found" when all the assets files were available under the virtual service project.
The issue was happening because the queue manager asset didn't have a queue manager name under the "Queue Manager:" field.
When looking at the asset file with a text editor we could see the following:
When the queue manager field is properly filled, the asset file will contain the following:
DevTest on release 10.1
Provide the proper Queue Manager name under the "Queue Manager" field for the Queue Manager asset.