Annoyance

[d000hg]

When the cause of the crash in your application turns out to be the debugging/tracing code you added to see what was going on.

[NickFitz]

When the cause of the crash in your application turns out to be the debugging/tracing code you added to see what was going on.

Or, indeed, the other way round: you add the debug/trace code, it stops crashing. Remove it, it crashes again

[NotAllThere]

What runs perfectly (and debuggerable) in foreground will fail in background.

[RSoles]

Ah yes, I remember a card which worked perfectly on an extender, back in the rack, dead as a dead thing.