JMeter 2.9 introduced a change in how configuration errors are handled for tests with multiple servers.
From the JMeter website:
"In remote Test mode, JMeter now exits in error if one of the remote engines cannot be configured, previously it started the test with available engines."
In other words, when using version 2.9, if any of the JMeter engines fails to start, the entire test will silently end.
In versions 2.8 and earlier, JMeter would start the test with how many test engines were available.
If this is not the behavior you are looking for, especially in tests that involve numerous test servers or Master Slave tests, we recommend to use JMeter 2.8 when possible.
Please note: We are working on a workaround to enable tests to run version 2.9 and not end if one of the remote engines cannot be configured.