SoapUI - Cannot wait on null future

Hi,

When running a high thread count I am getting the following errors in SoapUI:

java.lang.RuntimeException: cannot wait on null future

It is very intermittent and only seems to happen with a high thread count (20+)

I have built my test suite so that it is thread safe. There is one call out to a Test Case to increment an ID, which I call with the property “Run primary TestCase (with for running to finish)”.

Other than that it is fairly simple script in calling a set of SOAP requests.

I have switched off all assertions but still the issue persists. I am using SoapUI 5.0.0 (as this is the currently installed version on the corporate network).

Many thanks.