Your question is Navigating Major Research Roadblocks. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Tell me about the most significant roadblock you hit in a research project. Walk me through how you diagnosed the problem, how you decided what to try next when the path forward was unclear, and what outcome you ultimately drove.