I am running an application on the simplelink evaluation board MSP-EXDP432E401Y with the XDS110 debugger that is integrated into the eval board. When I insert a breakpoint into an ISR the break happens but I am unable to do anything but hit run again. There is no single stepping capability. Single stepping works fine outside the ISR. Is there a compiler setting that should be set?
Googling your "MSP-EXDP432E401Y" board leads me back here, You mean this?
http://www.ti.com/tool/MSP-EXP432E401Y
Is there something else interrupting the interrupt you've stalled?
Perhaps try some instrumentation to understand how you own code works/flows under dynamic conditions. Do you really need to single step an interrupt to know what it should be doing? Apply basic static analysis methods, and augment those with instrumentation and sanity checking. Record stuff to a play-back/trace buffer so you can better understand the dynamics and interplay with other interrupts, etc.