Tmr Svc appears to stop working and threads waiting for event bits become non-responsive - How should I debug this?

Kernel
3

Thank you for your input. I found the problems, I changed configTIMER_TASK_PRIORITY from 2 to ( configMAX_PRIORITIES - 1 ) and made sure no interrupts in my code have more urgent priorities than configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY.