Dynamic replacement of standard memory allocation routines with tbbmalloc is done via run-time modification of MSVCRTimage in the application address space, and it has global effect. For complex applications using 3rd party components, especially those from Microsoft that may e.g. use internal MSVCRT implementation details, it can cause problems. To understand what's going wrong, we would need a reproducing test. As a workaround, I may suggest you to analyze what modules of your app benefit most from the TBB allocator, and in these modules directly use the TBB allocator functions (scalable_malloc etc) instead of the standard routines. Admittedly, it is much more to do comparing to use of tbbmalloc_proxy, but might be worth it.