It sounds like you forgot to configure a VHost-level thread pool for the load test tool?
Ensure that you have followed step 4 in the
LoadTesingTool.pdf, as that's the error usually seen when that
configuration step is not included:
Step 4. The Load Testing tool requires the _defaultVHost_ virtual host (VHost) to have its
own thread pool. By default, Wowza Streaming Engine is configured to use a server-level thread pool. To configure a VHost-level thread pool, edit [install-dir]/conf/VHost.xml and make the following changes:
- HandlerThreadPool/PoolSize: 60 x [total-core-count]
- TransportThreadPool/PoolSize: 40 x [total-core-count]