I recently got asked to look at a site that was experiencing TM1 server crashes.
I had a look and found that on an MDX report that ran in Excel, it was referencing a dynamic subset. This dynamic subset was producing empty results due to changes in their structure.
Essentially whenever they ran this Excel MDX report it would crash the server instantly. As soon as I fixed the Dynamic Subset, the MDX report worked fine and the server is stable again.
I guess the lesson is to check that your dynamic subsets are never producing empty results.
