Assume that you use Microsoft SQL Server 2012 Analysis Service (SSAS 2012) or SSAS 2014. When you run a Multidimensional Expressions (MDX) query against a Many-To-Many dimension, the memory consumption increases very quickly, and surpasses HardMemoryLimit after some time. However, the MDX query may not be canceled as expected when the total consumed memory exceeds HardMemoryLimit. When physical memory is exhausted, the server may become unresponsive.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.