The test run is aborted when a .testsettings is used for executing JustMock tests. The .testsettings contains only a description.

<?xml version="1.0" encoding="UTF-8"?>
<TestSettings name="Local" id="15694c75-be1c-4113-9d42-2cbe1013c41c" xmlns="http://microsoft.com/schemas/VisualStudio/TeamTest/2010">
  <Description>These are default test settings for a local test run.</Description>
</TestSettings>

It seems that the usage of the MSTest element is breaking the execution.

Workaround: As .testsettings are deprecated use .runsettings instead without MSTest element.