Memory leaks of a running program. You should consider at what stage memory leak manifests and check all invoked code.

Thanks for your answers.

Agreed, leverage the tools.

A consistent crash is actually one of the easiest. Look at the call stack at the moment of the crash. Look at the pointers and data. If needed drop a breakpoint and restart to peek into the moment before the crash. Static analysis tools can point out language misuse, like mismatch of array and individual versions. . Diagnostic libraries can use memory markers, data breakpoints, allocation / leak tracking, and other tools to catch runtime errors.

Much harder are seemingly random crashes from bugs that unexpectedly overwrite data, like race conditions in parallel code or stale pointers being accessed.

Thank you for your advices.